diff --git a/dom/base/ImportManager.cpp b/dom/base/ImportManager.cpp
index 1f4d376b37b5..d0e514b59161 100644
--- a/dom/base/ImportManager.cpp
+++ b/dom/base/ImportManager.cpp
@@ -6,7 +6,6 @@
 
 #include "ImportManager.h"
 
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/EventListenerManager.h"
 #include "HTMLLinkElement.h"
 #include "nsContentPolicyUtils.h"
@@ -19,6 +18,7 @@
 #include "nsIDOMEvent.h"
 #include "nsIPrincipal.h"
 #include "nsIScriptObjectPrincipal.h"
+#include "nsScriptLoader.h"
 #include "nsNetUtil.h"
 
 //-----------------------------------------------------------------------------
@@ -156,7 +156,7 @@ ImportLoader::Updater::UpdateMainReferrer(uint32_t aNewIdx)
     // Our nearest predecessor has changed. So let's add the ScriptLoader to the
     // new one if there is any. And remove it from the old one.
     RefPtr<ImportManager> manager = mLoader->Manager();
-    ScriptLoader* loader = mLoader->mDocument->ScriptLoader();
+    nsScriptLoader* loader = mLoader->mDocument->ScriptLoader();
     ImportLoader*& pred = mLoader->mBlockingPredecessor;
     ImportLoader* newPred = manager->GetNearestPredecessor(newMainReferrer);
     if (pred) {
@@ -339,7 +339,7 @@ ImportLoader::DispatchEventIfFinished(nsINode* aNode)
 }
 
 void
-ImportLoader::AddBlockedScriptLoader(ScriptLoader* aScriptLoader)
+ImportLoader::AddBlockedScriptLoader(nsScriptLoader* aScriptLoader)
 {
   if (mBlockedScriptLoaders.Contains(aScriptLoader)) {
     return;
@@ -352,7 +352,7 @@ ImportLoader::AddBlockedScriptLoader(ScriptLoader* aScriptLoader)
 }
 
 bool
-ImportLoader::RemoveBlockedScriptLoader(ScriptLoader* aScriptLoader)
+ImportLoader::RemoveBlockedScriptLoader(nsScriptLoader* aScriptLoader)
 {
   aScriptLoader->RemoveParserBlockingScriptExecutionBlocker();
   return mBlockedScriptLoaders.RemoveElement(aScriptLoader);
diff --git a/dom/base/ImportManager.h b/dom/base/ImportManager.h
index ccc00125ae58..258d4691cf7f 100644
--- a/dom/base/ImportManager.h
+++ b/dom/base/ImportManager.h
@@ -45,8 +45,8 @@
 #include "nsIStreamListener.h"
 #include "nsIWeakReferenceUtils.h"
 #include "nsRefPtrHashtable.h"
+#include "nsScriptLoader.h"
 #include "nsURIHashKey.h"
-#include "mozilla/dom/ScriptLoader.h"
 
 class nsIDocument;
 class nsIPrincipal;
@@ -184,8 +184,8 @@ public:
   // and wait for that to run its scripts. We keep track of all the
   // ScriptRunners that are waiting for this import. NOTE: updating
   // the main referrer might change this list.
-  void AddBlockedScriptLoader(ScriptLoader* aScriptLoader);
-  bool RemoveBlockedScriptLoader(ScriptLoader* aScriptLoader);
+  void AddBlockedScriptLoader(nsScriptLoader* aScriptLoader);
+  bool RemoveBlockedScriptLoader(nsScriptLoader* aScriptLoader);
   void SetBlockingPredecessor(ImportLoader* aLoader);
 
 private:
@@ -230,7 +230,7 @@ private:
 
   // List of pending ScriptLoaders that are waiting for this import
   // to finish.
-  nsTArray<RefPtr<ScriptLoader>> mBlockedScriptLoaders;
+  nsTArray<RefPtr<nsScriptLoader>> mBlockedScriptLoaders;
 
   // There is always exactly one referrer link that is flagged as
   // the main referrer the primary link. This is the one that is
diff --git a/dom/base/Location.cpp b/dom/base/Location.cpp
index f437250f20d3..6a269fe631e4 100644
--- a/dom/base/Location.cpp
+++ b/dom/base/Location.cpp
@@ -32,9 +32,9 @@
 #include "mozilla/Likely.h"
 #include "nsCycleCollectionParticipant.h"
 #include "NullPrincipal.h"
+#include "ScriptSettings.h"
 #include "mozilla/Unused.h"
 #include "mozilla/dom/LocationBinding.h"
-#include "mozilla/dom/ScriptSettings.h"
 
 namespace mozilla {
 namespace dom {
diff --git a/dom/script/ScriptSettings.cpp b/dom/base/ScriptSettings.cpp
similarity index 100%
rename from dom/script/ScriptSettings.cpp
rename to dom/base/ScriptSettings.cpp
diff --git a/dom/script/ScriptSettings.h b/dom/base/ScriptSettings.h
similarity index 100%
rename from dom/script/ScriptSettings.h
rename to dom/base/ScriptSettings.h
diff --git a/dom/base/moz.build b/dom/base/moz.build
index 4b4f0063f49d..cc41636b3fbe 100644
--- a/dom/base/moz.build
+++ b/dom/base/moz.build
@@ -27,6 +27,7 @@ XPIDL_SOURCES += [
     'nsIObjectLoadingContent.idl',
     'nsIRemoteWindowContext.idl',
     'nsIScriptChannel.idl',
+    'nsIScriptLoaderObserver.idl',
     'nsISelection.idl',
     'nsISelectionController.idl',
     'nsISelectionDisplay.idl',
@@ -91,6 +92,7 @@ EXPORTS += [
     'nsINode.h',
     'nsINodeList.h',
     'nsIScriptContext.h',
+    'nsIScriptElement.h',
     'nsIScriptGlobalObject.h',
     'nsIScriptNameSpaceManager.h',
     'nsIScriptObjectPrincipal.h',
@@ -111,6 +113,7 @@ EXPORTS += [
     'nsRange.h',
     'nsReferencedElement.h',
     'nsSandboxFlags.h',
+    'nsScriptLoader.h',
     'nsStructuredCloneContainer.h',
     'nsStubAnimationObserver.h',
     'nsStubDocumentObserver.h',
@@ -195,6 +198,7 @@ EXPORTS.mozilla.dom += [
     'ResponsiveImageSelector.h',
     'SameProcessMessageQueue.h',
     'ScreenOrientation.h',
+    'ScriptSettings.h',
     'ShadowRoot.h',
     'StructuredCloneHolder.h',
     'StructuredCloneTags.h',
@@ -311,6 +315,8 @@ UNIFIED_SOURCES += [
     'nsRange.cpp',
     'nsReferencedElement.cpp',
     'nsScreen.cpp',
+    'nsScriptElement.cpp',
+    'nsScriptLoader.cpp',
     'nsScriptNameSpaceManager.cpp',
     'nsStructuredCloneContainer.cpp',
     'nsStubAnimationObserver.cpp',
@@ -337,6 +343,7 @@ UNIFIED_SOURCES += [
     'ResponsiveImageSelector.cpp',
     'SameProcessMessageQueue.cpp',
     'ScreenOrientation.cpp',
+    'ScriptSettings.cpp',
     'ShadowRoot.cpp',
     'StructuredCloneHolder.cpp',
     'StyleSheetList.cpp',
diff --git a/dom/base/nsContentPermissionHelper.cpp b/dom/base/nsContentPermissionHelper.cpp
index 535262a3f437..49b58aebed10 100644
--- a/dom/base/nsContentPermissionHelper.cpp
+++ b/dom/base/nsContentPermissionHelper.cpp
@@ -32,6 +32,7 @@
 #include "nsIDocument.h"
 #include "nsIDOMEvent.h"
 #include "nsWeakPtr.h"
+#include "ScriptSettings.h"
 
 using mozilla::Unused;          // <snicker>
 using namespace mozilla::dom;
diff --git a/dom/base/nsContentSink.cpp b/dom/base/nsContentSink.cpp
index 0c94aec06920..762b49ab8883 100644
--- a/dom/base/nsContentSink.cpp
+++ b/dom/base/nsContentSink.cpp
@@ -10,6 +10,7 @@
  */
 
 #include "nsContentSink.h"
+#include "nsScriptLoader.h"
 #include "nsIDocument.h"
 #include "nsIDOMDocument.h"
 #include "mozilla/css/Loader.h"
@@ -48,7 +49,6 @@
 #include "nsHTMLDNSPrefetch.h"
 #include "nsIObserverService.h"
 #include "mozilla/Preferences.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "nsParserConstants.h"
 #include "nsSandboxFlags.h"
 
diff --git a/dom/base/nsContentSink.h b/dom/base/nsContentSink.h
index ae5c5e92eab7..af211ae462a2 100644
--- a/dom/base/nsContentSink.h
+++ b/dom/base/nsContentSink.h
@@ -36,16 +36,13 @@ class nsIAtom;
 class nsIChannel;
 class nsIContent;
 class nsNodeInfoManager;
+class nsScriptLoader;
 class nsIApplicationCache;
 
 namespace mozilla {
 namespace css {
 class Loader;
 } // namespace css
-
-namespace dom {
-class ScriptLoader;
-} // namespace dom
 } // namespace mozilla
 
 #ifdef DEBUG
@@ -279,7 +276,7 @@ protected:
   nsCOMPtr<nsIDocShell>         mDocShell;
   RefPtr<mozilla::css::Loader> mCSSLoader;
   RefPtr<nsNodeInfoManager>   mNodeInfoManager;
-  RefPtr<mozilla::dom::ScriptLoader> mScriptLoader;
+  RefPtr<nsScriptLoader>      mScriptLoader;
 
   // back off timer notification after count
   int32_t mBackoffCount;
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index af9ea0adbdf5..7068149e2f48 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -2026,7 +2026,7 @@ nsDocument::Init()
   mScopeObject = do_GetWeakReference(global);
   MOZ_ASSERT(mScopeObject);
 
-  mScriptLoader = new dom::ScriptLoader(this);
+  mScriptLoader = new nsScriptLoader(this);
 
   mozilla::HoldJSObjects(this);
 
@@ -5011,7 +5011,7 @@ nsDocument::GetWindowInternal() const
   return win;
 }
 
-ScriptLoader*
+nsScriptLoader*
 nsDocument::ScriptLoader()
 {
   return mScriptLoader;
diff --git a/dom/base/nsDocument.h b/dom/base/nsDocument.h
index 8a1663e4c78b..c3efcef6f1a4 100644
--- a/dom/base/nsDocument.h
+++ b/dom/base/nsDocument.h
@@ -31,6 +31,7 @@
 #include "nsJSThingHashtable.h"
 #include "nsIScriptObjectPrincipal.h"
 #include "nsIURI.h"
+#include "nsScriptLoader.h"
 #include "nsIRadioGroupContainer.h"
 #include "nsILayoutHistoryState.h"
 #include "nsIRequest.h"
@@ -59,7 +60,6 @@
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/PendingAnimationTracker.h"
 #include "mozilla/dom/DOMImplementation.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/dom/StyleSheetList.h"
 #include "nsDataHashtable.h"
 #include "mozilla/TimeStamp.h"
@@ -742,7 +742,7 @@ public:
   /**
    * Get the script loader for this document
    */
-  virtual mozilla::dom::ScriptLoader* ScriptLoader() override;
+  virtual nsScriptLoader* ScriptLoader() override;
 
   /**
    * Add/Remove an element to the document's id and name hashes
@@ -1492,7 +1492,7 @@ public:
   RefPtr<mozilla::EventListenerManager> mListenerManager;
   RefPtr<mozilla::dom::StyleSheetList> mDOMStyleSheets;
   RefPtr<nsDOMStyleSheetSetList> mStyleSheetSetList;
-  RefPtr<mozilla::dom::ScriptLoader> mScriptLoader;
+  RefPtr<nsScriptLoader> mScriptLoader;
   nsDocHeaderData* mHeaderData;
   /* mIdentifierMap works as follows for IDs:
    * 1) Attribute changes affect the table immediately (removing and adding
diff --git a/dom/base/nsFrameMessageManager.cpp b/dom/base/nsFrameMessageManager.cpp
index 6ef8a12bd90b..ae3c54f3f322 100644
--- a/dom/base/nsFrameMessageManager.cpp
+++ b/dom/base/nsFrameMessageManager.cpp
@@ -18,7 +18,7 @@
 #include "nsJSUtils.h"
 #include "nsJSPrincipals.h"
 #include "nsNetUtil.h"
-#include "mozilla/dom/ScriptLoader.h"
+#include "nsScriptLoader.h"
 #include "nsFrameLoader.h"
 #include "nsIInputStream.h"
 #include "nsIXULRuntime.h"
@@ -1640,9 +1640,9 @@ nsMessageManagerScriptExecutor::TryCacheLoadAndCompileScript(
       if (NS_FAILED(NS_ReadInputStreamToString(input, buffer, avail))) {
         return;
       }
-      ScriptLoader::ConvertToUTF16(channel, (uint8_t*)buffer.get(), avail,
-                                   EmptyString(), nullptr,
-                                   dataStringBuf, dataStringLength);
+      nsScriptLoader::ConvertToUTF16(channel, (uint8_t*)buffer.get(), avail,
+                                     EmptyString(), nullptr,
+                                     dataStringBuf, dataStringLength);
     }
 
     JS::SourceBufferHolder srcBuf(dataStringBuf, dataStringLength,
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 20d71578cace..d9fc5f615495 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -64,7 +64,7 @@
 #include "nsReadableUtils.h"
 #include "nsDOMClassInfo.h"
 #include "nsJSEnvironment.h"
-#include "mozilla/dom/ScriptSettings.h"
+#include "ScriptSettings.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/Likely.h"
 #include "mozilla/Sprintf.h"
diff --git a/dom/base/nsIDocument.h b/dom/base/nsIDocument.h
index 930943082cbe..5b4955952fd2 100644
--- a/dom/base/nsIDocument.h
+++ b/dom/base/nsIDocument.h
@@ -92,6 +92,7 @@ class nsIVariant;
 class nsViewManager;
 class nsPresContext;
 class nsRange;
+class nsScriptLoader;
 class nsSMILAnimationController;
 class nsSVGElement;
 class nsTextNode;
@@ -153,7 +154,6 @@ class NodeIterator;
 enum class OrientationType : uint8_t;
 class ProcessingInstruction;
 class Promise;
-class ScriptLoader;
 class StyleSheetList;
 class SVGDocument;
 class SVGSVGElement;
@@ -1368,7 +1368,7 @@ public:
   /**
    * Get the script loader for this document
    */
-  virtual mozilla::dom::ScriptLoader* ScriptLoader() = 0;
+  virtual nsScriptLoader* ScriptLoader() = 0;
 
   /**
    * Add/Remove an element to the document's id and name hashes
diff --git a/dom/script/nsIScriptElement.h b/dom/base/nsIScriptElement.h
similarity index 100%
rename from dom/script/nsIScriptElement.h
rename to dom/base/nsIScriptElement.h
diff --git a/dom/script/nsIScriptLoaderObserver.idl b/dom/base/nsIScriptLoaderObserver.idl
similarity index 100%
rename from dom/script/nsIScriptLoaderObserver.idl
rename to dom/base/nsIScriptLoaderObserver.idl
diff --git a/dom/base/nsInProcessTabChildGlobal.cpp b/dom/base/nsInProcessTabChildGlobal.cpp
index 302e6eaef1fd..ca2f4be6f9cd 100644
--- a/dom/base/nsInProcessTabChildGlobal.cpp
+++ b/dom/base/nsInProcessTabChildGlobal.cpp
@@ -11,13 +11,13 @@
 #include "nsIComponentManager.h"
 #include "nsIServiceManager.h"
 #include "nsComponentManagerUtils.h"
+#include "nsScriptLoader.h"
 #include "nsFrameLoader.h"
 #include "xpcpublic.h"
 #include "nsIMozBrowserFrame.h"
 #include "nsDOMClassInfoID.h"
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/dom/SameProcessMessageQueue.h"
-#include "mozilla/dom/ScriptLoader.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
diff --git a/dom/base/nsJSEnvironment.cpp b/dom/base/nsJSEnvironment.cpp
index 606f76859314..8946d75a9833 100644
--- a/dom/base/nsJSEnvironment.cpp
+++ b/dom/base/nsJSEnvironment.cpp
@@ -37,6 +37,7 @@
 #include "nsXPCOMCIDInternal.h"
 #include "nsIXULRuntime.h"
 #include "nsTextFormatter.h"
+#include "ScriptSettings.h"
 #ifdef XP_WIN
 #include <process.h>
 #define getpid _getpid
@@ -59,7 +60,6 @@
 #include "mozilla/dom/DOMException.h"
 #include "mozilla/dom/DOMExceptionBinding.h"
 #include "mozilla/dom/ErrorEvent.h"
-#include "mozilla/dom/ScriptSettings.h"
 #include "nsAXPCNativeCallContext.h"
 #include "mozilla/CycleCollectedJSRuntime.h"
 #include "mozilla/SystemGroup.h"
diff --git a/dom/script/ScriptElement.cpp b/dom/base/nsScriptElement.cpp
similarity index 64%
rename from dom/script/ScriptElement.cpp
rename to dom/base/nsScriptElement.cpp
index 0cb17dcb0656..ebeb18f81cb2 100644
--- a/dom/script/ScriptElement.cpp
+++ b/dom/base/nsScriptElement.cpp
@@ -4,13 +4,13 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#include "ScriptElement.h"
-#include "ScriptLoader.h"
+#include "nsScriptElement.h"
 #include "mozilla/BasicEvents.h"
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/dom/Element.h"
 #include "nsContentUtils.h"
 #include "nsPresContext.h"
+#include "nsScriptLoader.h"
 #include "nsIParser.h"
 #include "nsGkAtoms.h"
 #include "nsContentSink.h"
@@ -19,11 +19,11 @@ using namespace mozilla;
 using namespace mozilla::dom;
 
 NS_IMETHODIMP
-ScriptElement::ScriptAvailable(nsresult aResult,
-                               nsIScriptElement *aElement,
-                               bool aIsInline,
-                               nsIURI *aURI,
-                               int32_t aLineNo)
+nsScriptElement::ScriptAvailable(nsresult aResult,
+                                 nsIScriptElement *aElement,
+                                 bool aIsInline,
+                                 nsIURI *aURI,
+                                 int32_t aLineNo)
 {
   if (!aIsInline && NS_FAILED(aResult)) {
     nsCOMPtr<nsIParser> parser = do_QueryReferent(mCreatorParser);
@@ -40,7 +40,7 @@ ScriptElement::ScriptAvailable(nsresult aResult,
 }
 
 /* virtual */ nsresult
-ScriptElement::FireErrorEvent()
+nsScriptElement::FireErrorEvent()
 {
   nsCOMPtr<nsIContent> cont =
     do_QueryInterface((nsIScriptElement*) this);
@@ -53,9 +53,9 @@ ScriptElement::FireErrorEvent()
 }
 
 NS_IMETHODIMP
-ScriptElement::ScriptEvaluated(nsresult aResult,
-                               nsIScriptElement *aElement,
-                               bool aIsInline)
+nsScriptElement::ScriptEvaluated(nsresult aResult,
+                                 nsIScriptElement *aElement,
+                                 bool aIsInline)
 {
   nsresult rv = NS_OK;
   if (!aIsInline) {
@@ -78,44 +78,44 @@ ScriptElement::ScriptEvaluated(nsresult aResult,
 }
 
 void
-ScriptElement::CharacterDataChanged(nsIDocument *aDocument,
-                                    nsIContent* aContent,
-                                    CharacterDataChangeInfo* aInfo)
+nsScriptElement::CharacterDataChanged(nsIDocument *aDocument,
+                                      nsIContent* aContent,
+                                      CharacterDataChangeInfo* aInfo)
 {
   MaybeProcessScript();
 }
 
 void
-ScriptElement::AttributeChanged(nsIDocument* aDocument,
-                                Element* aElement,
-                                int32_t aNameSpaceID,
-                                nsIAtom* aAttribute,
-                                int32_t aModType,
-                                const nsAttrValue* aOldValue)
+nsScriptElement::AttributeChanged(nsIDocument* aDocument,
+                                  Element* aElement,
+                                  int32_t aNameSpaceID,
+                                  nsIAtom* aAttribute,
+                                  int32_t aModType,
+                                  const nsAttrValue* aOldValue)
 {
   MaybeProcessScript();
 }
 
 void
-ScriptElement::ContentAppended(nsIDocument* aDocument,
-                               nsIContent* aContainer,
-                               nsIContent* aFirstNewContent,
-                               int32_t aNewIndexInContainer)
+nsScriptElement::ContentAppended(nsIDocument* aDocument,
+                                 nsIContent* aContainer,
+                                 nsIContent* aFirstNewContent,
+                                 int32_t aNewIndexInContainer)
 {
   MaybeProcessScript();
 }
 
 void
-ScriptElement::ContentInserted(nsIDocument *aDocument,
-                               nsIContent* aContainer,
-                               nsIContent* aChild,
-                               int32_t aIndexInContainer)
+nsScriptElement::ContentInserted(nsIDocument *aDocument,
+                                 nsIContent* aContainer,
+                                 nsIContent* aChild,
+                                 int32_t aIndexInContainer)
 {
   MaybeProcessScript();
 }
 
 bool
-ScriptElement::MaybeProcessScript()
+nsScriptElement::MaybeProcessScript()
 {
   nsCOMPtr<nsIContent> cont =
     do_QueryInterface((nsIScriptElement*) this);
@@ -145,6 +145,6 @@ ScriptElement::MaybeProcessScript()
     }
   }
 
-  RefPtr<ScriptLoader> loader = ownerDoc->ScriptLoader();
+  RefPtr<nsScriptLoader> loader = ownerDoc->ScriptLoader();
   return loader->ProcessScriptElement(this);
 }
diff --git a/dom/script/ScriptElement.h b/dom/base/nsScriptElement.h
similarity index 78%
rename from dom/script/ScriptElement.h
rename to dom/base/nsScriptElement.h
index 0babda674af1..4a2a584ac2e7 100644
--- a/dom/script/ScriptElement.h
+++ b/dom/base/nsScriptElement.h
@@ -4,25 +4,22 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#ifndef mozilla_dom_ScriptElement_h
-#define mozilla_dom_ScriptElement_h
+#ifndef nsScriptElement_h
+#define nsScriptElement_h
 
 #include "mozilla/Attributes.h"
 #include "nsIScriptLoaderObserver.h"
 #include "nsIScriptElement.h"
 #include "nsStubMutationObserver.h"
 
-namespace mozilla {
-namespace dom {
-
 /**
  * Baseclass useful for script elements (such as <xhtml:script> and
  * <svg:script>). Currently the class assumes that only the 'src'
  * attribute and the children of the class affect what script to execute.
  */
 
-class ScriptElement : public nsIScriptElement,
-                      public nsStubMutationObserver
+class nsScriptElement : public nsIScriptElement,
+                        public nsStubMutationObserver
 {
 public:
   // nsIScriptLoaderObserver
@@ -34,7 +31,7 @@ public:
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
 
-  explicit ScriptElement(FromParser aFromParser)
+  explicit nsScriptElement(mozilla::dom::FromParser aFromParser)
     : nsIScriptElement(aFromParser)
   {
   }
@@ -52,7 +49,4 @@ protected:
   virtual bool MaybeProcessScript() override;
 };
 
-} // dom namespace
-} // mozilla namespace
-
-#endif // mozilla_dom_ScriptElement_h
+#endif // nsScriptElement_h
diff --git a/dom/script/ScriptLoader.cpp b/dom/base/nsScriptLoader.cpp
similarity index 86%
rename from dom/script/ScriptLoader.cpp
rename to dom/base/nsScriptLoader.cpp
index f90c30bd021f..5a5ebf5802a0 100644
--- a/dom/script/ScriptLoader.cpp
+++ b/dom/base/nsScriptLoader.cpp
@@ -8,7 +8,7 @@
  * A class that handles loading and evaluation of <script> elements.
  */
 
-#include "ScriptLoader.h"
+#include "nsScriptLoader.h"
 
 #include "prsystem.h"
 #include "jsapi.h"
@@ -59,15 +59,14 @@
 
 #include "mozilla/AsyncEventDispatcher.h"
 #include "mozilla/Attributes.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/Unused.h"
 #include "nsIScriptError.h"
 #include "nsIOutputStream.h"
 
-using JS::SourceBufferHolder;
+using namespace mozilla;
+using namespace mozilla::dom;
 
-namespace mozilla {
-namespace dom {
+using JS::SourceBufferHolder;
 
 static LazyLogModule gCspPRLog("CSP");
 static LazyLogModule gScriptLoaderLog("ScriptLoader");
@@ -83,18 +82,18 @@ static LazyLogModule gScriptLoaderLog("ScriptLoader");
 
 #define LOG_ENABLED() MOZ_LOG_TEST(gScriptLoaderLog, mozilla::LogLevel::Debug)
 
-// These are the Alternate Data MIME type used by the ScriptLoader to
+// These are the Alternate Data MIME type used by the nsScriptLoader to
 // register and read bytecode out of the nsCacheInfoChannel.
 static NS_NAMED_LITERAL_CSTRING(
   kBytecodeMimeType, "javascript/moz-bytecode-" NS_STRINGIFY(MOZ_BUILDID));
 static NS_NAMED_LITERAL_CSTRING(kNullMimeType, "javascript/null");
 
 void
-ImplCycleCollectionUnlink(ScriptLoadRequestList& aField);
+ImplCycleCollectionUnlink(nsScriptLoadRequestList& aField);
 
 void
 ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
-                            ScriptLoadRequestList& aField,
+                            nsScriptLoadRequestList& aField,
                             const char* aName,
                             uint32_t aFlags = 0);
 
@@ -145,31 +144,31 @@ TestingDispatchEvent(nsIScriptElement* aScriptElement,
 }
 
 //////////////////////////////////////////////////////////////
-// ScriptLoadRequest
+// nsScriptLoadRequest
 //////////////////////////////////////////////////////////////
 
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ScriptLoadRequest)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsScriptLoadRequest)
 NS_INTERFACE_MAP_END
 
-NS_IMPL_CYCLE_COLLECTING_ADDREF(ScriptLoadRequest)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(ScriptLoadRequest)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsScriptLoadRequest)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsScriptLoadRequest)
 
-NS_IMPL_CYCLE_COLLECTION_CLASS(ScriptLoadRequest)
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsScriptLoadRequest)
 
-NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(ScriptLoadRequest)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsScriptLoadRequest)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mCacheInfo)
   tmp->DropBytecodeCacheReferences();
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(ScriptLoadRequest)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsScriptLoadRequest)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCacheInfo)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
-NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(ScriptLoadRequest)
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsScriptLoadRequest)
   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mScript)
 NS_IMPL_CYCLE_COLLECTION_TRACE_END
 
-ScriptLoadRequest::~ScriptLoadRequest()
+nsScriptLoadRequest::~nsScriptLoadRequest()
 {
   // We should always clean up any off-thread script parsing resources.
   MOZ_ASSERT(!mOffThreadToken);
@@ -184,21 +183,21 @@ ScriptLoadRequest::~ScriptLoadRequest()
 }
 
 void
-ScriptLoadRequest::SetReady()
+nsScriptLoadRequest::SetReady()
 {
   MOZ_ASSERT(mProgress != Progress::Ready);
   mProgress = Progress::Ready;
 }
 
 void
-ScriptLoadRequest::Cancel()
+nsScriptLoadRequest::Cancel()
 {
   MaybeCancelOffThreadScript();
   mIsCanceled = true;
 }
 
 void
-ScriptLoadRequest::MaybeCancelOffThreadScript()
+nsScriptLoadRequest::MaybeCancelOffThreadScript()
 {
   MOZ_ASSERT(NS_IsMainThread());
 
@@ -207,7 +206,7 @@ ScriptLoadRequest::MaybeCancelOffThreadScript()
   }
 
   JSContext* cx = danger::GetJSContext();
-  // Follow the same conditions as ScriptLoader::AttemptAsyncScriptCompile
+  // Follow the same conditions as nsScriptLoader::AttemptAsyncScriptCompile
   if (IsModuleRequest()) {
     JS::CancelOffThreadModule(cx, mOffThreadToken);
   } else if (IsSource()) {
@@ -220,29 +219,29 @@ ScriptLoadRequest::MaybeCancelOffThreadScript()
 }
 
 //////////////////////////////////////////////////////////////
-// ModuleLoadRequest
+// nsModuleLoadRequest
 //////////////////////////////////////////////////////////////
 
 // A load request for a module, created for every top level module script and
-// every module import.  Load request can share an ModuleScript if there are
+// every module import.  Load request can share an nsModuleScript if there are
 // multiple imports of the same module.
 
-class ModuleLoadRequest final : public ScriptLoadRequest
+class nsModuleLoadRequest final : public nsScriptLoadRequest
 {
-  ~ModuleLoadRequest() = default;
+  ~nsModuleLoadRequest() {}
 
-  ModuleLoadRequest(const ModuleLoadRequest& aOther) = delete;
-  ModuleLoadRequest(ModuleLoadRequest&& aOther) = delete;
+  nsModuleLoadRequest(const nsModuleLoadRequest& aOther) = delete;
+  nsModuleLoadRequest(nsModuleLoadRequest&& aOther) = delete;
 
 public:
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ModuleLoadRequest, ScriptLoadRequest)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsModuleLoadRequest, nsScriptLoadRequest)
 
-  ModuleLoadRequest(nsIScriptElement* aElement,
-                    uint32_t aVersion,
-                    CORSMode aCORSMode,
-                    const SRIMetadata& aIntegrity,
-                    ScriptLoader* aLoader);
+  nsModuleLoadRequest(nsIScriptElement* aElement,
+                      uint32_t aVersion,
+                      CORSMode aCORSMode,
+                      const SRIMetadata& aIntegrity,
+                      nsScriptLoader* aLoader);
 
   bool IsTopLevel() const {
     return mIsTopLevel;
@@ -263,15 +262,15 @@ public:
 
   // Pointer to the script loader, used to trigger actions when the module load
   // finishes.
-  RefPtr<ScriptLoader> mLoader;
+  RefPtr<nsScriptLoader> mLoader;
 
   // The importing module, or nullptr for top level module scripts.  Used to
   // implement the ancestor list checked when fetching module dependencies.
-  RefPtr<ModuleLoadRequest> mParent;
+  RefPtr<nsModuleLoadRequest> mParent;
 
   // Set to a module script object after a successful load or nullptr on
   // failure.
-  RefPtr<ModuleScript> mModuleScript;
+  RefPtr<nsModuleScript> mModuleScript;
 
   // A promise that is completed on successful load of this module and all of
   // its dependencies, indicating that the module is ready for instantiation and
@@ -279,48 +278,48 @@ public:
   MozPromiseHolder<GenericPromise> mReady;
 
   // Array of imported modules.
-  nsTArray<RefPtr<ModuleLoadRequest>> mImports;
+  nsTArray<RefPtr<nsModuleLoadRequest>> mImports;
 };
 
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(ModuleLoadRequest)
-NS_INTERFACE_MAP_END_INHERITING(ScriptLoadRequest)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(nsModuleLoadRequest)
+NS_INTERFACE_MAP_END_INHERITING(nsScriptLoadRequest)
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(ModuleLoadRequest, ScriptLoadRequest,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(nsModuleLoadRequest, nsScriptLoadRequest,
                                    mBaseURL,
                                    mLoader,
                                    mParent,
                                    mModuleScript,
                                    mImports)
 
-NS_IMPL_ADDREF_INHERITED(ModuleLoadRequest, ScriptLoadRequest)
-NS_IMPL_RELEASE_INHERITED(ModuleLoadRequest, ScriptLoadRequest)
+NS_IMPL_ADDREF_INHERITED(nsModuleLoadRequest, nsScriptLoadRequest)
+NS_IMPL_RELEASE_INHERITED(nsModuleLoadRequest, nsScriptLoadRequest)
 
-ModuleLoadRequest::ModuleLoadRequest(nsIScriptElement* aElement,
-                                     uint32_t aVersion,
-                                     CORSMode aCORSMode,
-                                     const SRIMetadata &aIntegrity,
-                                     ScriptLoader* aLoader)
-  : ScriptLoadRequest(ScriptKind::Module,
-                      aElement,
-                      aVersion,
-                      aCORSMode,
-                      aIntegrity),
+nsModuleLoadRequest::nsModuleLoadRequest(nsIScriptElement* aElement,
+                                         uint32_t aVersion,
+                                         CORSMode aCORSMode,
+                                         const SRIMetadata &aIntegrity,
+                                         nsScriptLoader* aLoader)
+  : nsScriptLoadRequest(nsScriptKind::Module,
+                        aElement,
+                        aVersion,
+                        aCORSMode,
+                        aIntegrity),
     mIsTopLevel(true),
     mLoader(aLoader)
 {}
 
-inline ModuleLoadRequest*
-ScriptLoadRequest::AsModuleRequest()
+inline nsModuleLoadRequest*
+nsScriptLoadRequest::AsModuleRequest()
 {
   MOZ_ASSERT(IsModuleRequest());
-  return static_cast<ModuleLoadRequest*>(this);
+  return static_cast<nsModuleLoadRequest*>(this);
 }
 
-void ModuleLoadRequest::Cancel()
+void nsModuleLoadRequest::Cancel()
 {
-  ScriptLoadRequest::Cancel();
+  nsScriptLoadRequest::Cancel();
   mModuleScript = nullptr;
-  mProgress = ScriptLoadRequest::Progress::Ready;
+  mProgress = nsScriptLoadRequest::Progress::Ready;
   for (size_t i = 0; i < mImports.Length(); i++) {
     mImports[i]->Cancel();
   }
@@ -328,7 +327,7 @@ void ModuleLoadRequest::Cancel()
 }
 
 void
-ModuleLoadRequest::SetReady()
+nsModuleLoadRequest::SetReady()
 {
 #ifdef DEBUG
   for (size_t i = 0; i < mImports.Length(); i++) {
@@ -336,12 +335,12 @@ ModuleLoadRequest::SetReady()
   }
 #endif
 
-  ScriptLoadRequest::SetReady();
+  nsScriptLoadRequest::SetReady();
   mReady.ResolveIfExists(true, __func__);
 }
 
 void
-ModuleLoadRequest::ModuleLoaded()
+nsModuleLoadRequest::ModuleLoaded()
 {
   // A module that was found to be marked as fetching in the module map has now
   // been loaded.
@@ -351,7 +350,7 @@ ModuleLoadRequest::ModuleLoaded()
 }
 
 void
-ModuleLoadRequest::DependenciesLoaded()
+nsModuleLoadRequest::DependenciesLoaded()
 {
   // The module and all of its dependencies have been successfully fetched and
   // compiled.
@@ -368,7 +367,7 @@ ModuleLoadRequest::DependenciesLoaded()
 }
 
 void
-ModuleLoadRequest::LoadFailed()
+nsModuleLoadRequest::LoadFailed()
 {
   Cancel();
   mLoader->ProcessLoadedModuleTree(this);
@@ -377,12 +376,12 @@ ModuleLoadRequest::LoadFailed()
 }
 
 //////////////////////////////////////////////////////////////
-// ModuleScript
+// nsModuleScript
 //////////////////////////////////////////////////////////////
 
 // A single module script.  May be used to satisfy multiple load requests.
 
-class ModuleScript final : public nsISupports
+class nsModuleScript final : public nsISupports
 {
   enum InstantiationState {
     Uninstantiated,
@@ -390,23 +389,23 @@ class ModuleScript final : public nsISupports
     Errored
   };
 
-  RefPtr<ScriptLoader> mLoader;
+  RefPtr<nsScriptLoader> mLoader;
   nsCOMPtr<nsIURI> mBaseURL;
   JS::Heap<JSObject*> mModuleRecord;
   JS::Heap<JS::Value> mException;
   InstantiationState mInstantiationState;
 
-  ~ModuleScript();
+  ~nsModuleScript();
 
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(ModuleScript)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsModuleScript)
 
-  ModuleScript(ScriptLoader* aLoader,
-               nsIURI* aBaseURL,
-               JS::Handle<JSObject*> aModuleRecord);
+  nsModuleScript(nsScriptLoader* aLoader,
+                 nsIURI* aBaseURL,
+                 JS::Handle<JSObject*> aModuleRecord);
 
-  ScriptLoader* Loader() const { return mLoader; }
+  nsScriptLoader* Loader() const { return mLoader; }
   JSObject* ModuleRecord() const { return mModuleRecord; }
   JS::Value Exception() const { return mException; }
   nsIURI* BaseURL() const { return mBaseURL; }
@@ -425,31 +424,31 @@ public:
   void UnlinkModuleRecord();
 };
 
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ModuleScript)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsModuleScript)
 NS_INTERFACE_MAP_END
 
-NS_IMPL_CYCLE_COLLECTION_CLASS(ModuleScript)
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsModuleScript)
 
-NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(ModuleScript)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsModuleScript)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mLoader)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mBaseURL)
   tmp->UnlinkModuleRecord();
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(ModuleScript)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsModuleScript)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLoader)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
-NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(ModuleScript)
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsModuleScript)
   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mModuleRecord)
   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mException)
 NS_IMPL_CYCLE_COLLECTION_TRACE_END
 
-NS_IMPL_CYCLE_COLLECTING_ADDREF(ModuleScript)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(ModuleScript)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsModuleScript)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsModuleScript)
 
-ModuleScript::ModuleScript(ScriptLoader *aLoader, nsIURI* aBaseURL,
-                           JS::Handle<JSObject*> aModuleRecord)
+nsModuleScript::nsModuleScript(nsScriptLoader *aLoader, nsIURI* aBaseURL,
+                               JS::Handle<JSObject*> aModuleRecord)
  : mLoader(aLoader),
    mBaseURL(aBaseURL),
    mModuleRecord(aModuleRecord),
@@ -467,7 +466,7 @@ ModuleScript::ModuleScript(ScriptLoader *aLoader, nsIURI* aBaseURL,
 }
 
 void
-ModuleScript::UnlinkModuleRecord()
+nsModuleScript::UnlinkModuleRecord()
 {
   // Remove module's back reference to this object request if present.
   if (mModuleRecord) {
@@ -479,7 +478,7 @@ ModuleScript::UnlinkModuleRecord()
   mException.setUndefined();
 }
 
-ModuleScript::~ModuleScript()
+nsModuleScript::~nsModuleScript()
 {
   if (mModuleRecord) {
     // The object may be destroyed without being unlinked first.
@@ -489,7 +488,7 @@ ModuleScript::~ModuleScript()
 }
 
 void
-ModuleScript::SetInstantiationResult(JS::Handle<JS::Value> aMaybeException)
+nsModuleScript::SetInstantiationResult(JS::Handle<JS::Value> aMaybeException)
 {
   MOZ_ASSERT(mInstantiationState == Uninstantiated);
   MOZ_ASSERT(mModuleRecord);
@@ -506,19 +505,19 @@ ModuleScript::SetInstantiationResult(JS::Handle<JS::Value> aMaybeException)
 
 //////////////////////////////////////////////////////////////
 
-// ScriptLoadRequestList
+// nsScriptLoadRequestList
 //////////////////////////////////////////////////////////////
 
-ScriptLoadRequestList::~ScriptLoadRequestList()
+nsScriptLoadRequestList::~nsScriptLoadRequestList()
 {
   Clear();
 }
 
 void
-ScriptLoadRequestList::Clear()
+nsScriptLoadRequestList::Clear()
 {
   while (!isEmpty()) {
-    RefPtr<ScriptLoadRequest> first = StealFirst();
+    RefPtr<nsScriptLoadRequest> first = StealFirst();
     first->Cancel();
     // And just let it go out of scope and die.
   }
@@ -526,9 +525,9 @@ ScriptLoadRequestList::Clear()
 
 #ifdef DEBUG
 bool
-ScriptLoadRequestList::Contains(ScriptLoadRequest* aElem) const
+nsScriptLoadRequestList::Contains(nsScriptLoadRequest* aElem) const
 {
-  for (const ScriptLoadRequest* req = getFirst();
+  for (const nsScriptLoadRequest* req = getFirst();
        req; req = req->getNext()) {
     if (req == aElem) {
       return true;
@@ -540,20 +539,20 @@ ScriptLoadRequestList::Contains(ScriptLoadRequest* aElem) const
 #endif // DEBUG
 
 inline void
-ImplCycleCollectionUnlink(ScriptLoadRequestList& aField)
+ImplCycleCollectionUnlink(nsScriptLoadRequestList& aField)
 {
   while (!aField.isEmpty()) {
-    RefPtr<ScriptLoadRequest> first = aField.StealFirst();
+    RefPtr<nsScriptLoadRequest> first = aField.StealFirst();
   }
 }
 
 inline void
 ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
-                            ScriptLoadRequestList& aField,
+                            nsScriptLoadRequestList& aField,
                             const char* aName,
                             uint32_t aFlags)
 {
-  for (ScriptLoadRequest* request = aField.getFirst();
+  for (nsScriptLoadRequest* request = aField.getFirst();
        request; request = request->getNext())
   {
     CycleCollectionNoteChild(aCallback, request, aName, aFlags);
@@ -561,18 +560,18 @@ ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
 }
 
 //////////////////////////////////////////////////////////////
-// ScriptLoader::PreloadInfo
+// nsScriptLoader::PreloadInfo
 //////////////////////////////////////////////////////////////
 
 inline void
-ImplCycleCollectionUnlink(ScriptLoader::PreloadInfo& aField)
+ImplCycleCollectionUnlink(nsScriptLoader::PreloadInfo& aField)
 {
   ImplCycleCollectionUnlink(aField.mRequest);
 }
 
 inline void
 ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
-                            ScriptLoader::PreloadInfo& aField,
+                            nsScriptLoader::PreloadInfo& aField,
                             const char* aName,
                             uint32_t aFlags = 0)
 {
@@ -580,13 +579,13 @@ ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
 }
 
 //////////////////////////////////////////////////////////////
-// ScriptLoader
+// nsScriptLoader
 //////////////////////////////////////////////////////////////
 
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ScriptLoader)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsScriptLoader)
 NS_INTERFACE_MAP_END
 
-NS_IMPL_CYCLE_COLLECTION(ScriptLoader,
+NS_IMPL_CYCLE_COLLECTION(nsScriptLoader,
                          mNonAsyncExternalScriptInsertedRequests,
                          mLoadingAsyncRequests,
                          mLoadedAsyncRequests,
@@ -597,10 +596,10 @@ NS_IMPL_CYCLE_COLLECTION(ScriptLoader,
                          mPendingChildLoaders,
                          mFetchedModules)
 
-NS_IMPL_CYCLE_COLLECTING_ADDREF(ScriptLoader)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(ScriptLoader)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsScriptLoader)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsScriptLoader)
 
-ScriptLoader::ScriptLoader(nsIDocument *aDocument)
+nsScriptLoader::nsScriptLoader(nsIDocument *aDocument)
   : mDocument(aDocument),
     mParserBlockingBlockerCount(0),
     mBlockerCount(0),
@@ -614,7 +613,7 @@ ScriptLoader::ScriptLoader(nsIDocument *aDocument)
 {
 }
 
-ScriptLoader::~ScriptLoader()
+nsScriptLoader::~nsScriptLoader()
 {
   mObservers.Clear();
 
@@ -622,27 +621,27 @@ ScriptLoader::~ScriptLoader()
     mParserBlockingRequest->FireScriptAvailable(NS_ERROR_ABORT);
   }
 
-  for (ScriptLoadRequest* req = mXSLTRequests.getFirst(); req;
+  for (nsScriptLoadRequest* req = mXSLTRequests.getFirst(); req;
        req = req->getNext()) {
     req->FireScriptAvailable(NS_ERROR_ABORT);
   }
 
-  for (ScriptLoadRequest* req = mDeferRequests.getFirst(); req;
+  for (nsScriptLoadRequest* req = mDeferRequests.getFirst(); req;
        req = req->getNext()) {
     req->FireScriptAvailable(NS_ERROR_ABORT);
   }
 
-  for (ScriptLoadRequest* req = mLoadingAsyncRequests.getFirst(); req;
+  for (nsScriptLoadRequest* req = mLoadingAsyncRequests.getFirst(); req;
        req = req->getNext()) {
     req->FireScriptAvailable(NS_ERROR_ABORT);
   }
 
-  for (ScriptLoadRequest* req = mLoadedAsyncRequests.getFirst(); req;
+  for (nsScriptLoadRequest* req = mLoadedAsyncRequests.getFirst(); req;
        req = req->getNext()) {
     req->FireScriptAvailable(NS_ERROR_ABORT);
   }
 
-  for(ScriptLoadRequest* req = mNonAsyncExternalScriptInsertedRequests.getFirst();
+  for(nsScriptLoadRequest* req = mNonAsyncExternalScriptInsertedRequests.getFirst();
       req;
       req = req->getNext()) {
     req->FireScriptAvailable(NS_ERROR_ABORT);
@@ -709,11 +708,11 @@ IsScriptEventHandler(nsIContent* aScriptElement)
 }
 
 nsresult
-ScriptLoader::CheckContentPolicy(nsIDocument* aDocument,
-                                 nsISupports *aContext,
-                                 nsIURI *aURI,
-                                 const nsAString &aType,
-                                 bool aIsPreLoad)
+nsScriptLoader::CheckContentPolicy(nsIDocument* aDocument,
+                                   nsISupports *aContext,
+                                   nsIURI *aURI,
+                                   const nsAString &aType,
+                                   bool aIsPreLoad)
 {
   nsContentPolicyType contentPolicyType = aIsPreLoad
                                           ? nsIContentPolicy::TYPE_INTERNAL_SCRIPT_PRELOAD
@@ -740,7 +739,7 @@ ScriptLoader::CheckContentPolicy(nsIDocument* aDocument,
 }
 
 bool
-ScriptLoader::ModuleScriptsEnabled()
+nsScriptLoader::ModuleScriptsEnabled()
 {
   static bool sEnabledForContent = false;
   static bool sCachedPref = false;
@@ -753,7 +752,7 @@ ScriptLoader::ModuleScriptsEnabled()
 }
 
 bool
-ScriptLoader::ModuleMapContainsModule(ModuleLoadRequest *aRequest) const
+nsScriptLoader::ModuleMapContainsModule(nsModuleLoadRequest *aRequest) const
 {
   // Returns whether we have fetched, or are currently fetching, a module script
   // for the request's URL.
@@ -762,7 +761,7 @@ ScriptLoader::ModuleMapContainsModule(ModuleLoadRequest *aRequest) const
 }
 
 bool
-ScriptLoader::IsFetchingModule(ModuleLoadRequest *aRequest) const
+nsScriptLoader::IsFetchingModule(nsModuleLoadRequest *aRequest) const
 {
   bool fetching = mFetchingModules.Contains(aRequest->mURI);
   MOZ_ASSERT_IF(fetching, !mFetchedModules.Contains(aRequest->mURI));
@@ -770,7 +769,7 @@ ScriptLoader::IsFetchingModule(ModuleLoadRequest *aRequest) const
 }
 
 void
-ScriptLoader::SetModuleFetchStarted(ModuleLoadRequest *aRequest)
+nsScriptLoader::SetModuleFetchStarted(nsModuleLoadRequest *aRequest)
 {
   // Update the module map to indicate that a module is currently being fetched.
 
@@ -780,8 +779,8 @@ ScriptLoader::SetModuleFetchStarted(ModuleLoadRequest *aRequest)
 }
 
 void
-ScriptLoader::SetModuleFetchFinishedAndResumeWaitingRequests(ModuleLoadRequest *aRequest,
-                                                             nsresult aResult)
+nsScriptLoader::SetModuleFetchFinishedAndResumeWaitingRequests(nsModuleLoadRequest *aRequest,
+                                                               nsresult aResult)
 {
   // Update module map with the result of fetching a single module script.  The
   // module script pointer is nullptr on error.
@@ -792,7 +791,7 @@ ScriptLoader::SetModuleFetchFinishedAndResumeWaitingRequests(ModuleLoadRequest *
   MOZ_ALWAYS_TRUE(mFetchingModules.Get(aRequest->mURI, getter_AddRefs(promise)));
   mFetchingModules.Remove(aRequest->mURI);
 
-  RefPtr<ModuleScript> ms(aRequest->mModuleScript);
+  RefPtr<nsModuleScript> ms(aRequest->mModuleScript);
   MOZ_ASSERT(NS_SUCCEEDED(aResult) == (ms != nullptr));
   mFetchedModules.Put(aRequest->mURI, ms);
 
@@ -806,7 +805,7 @@ ScriptLoader::SetModuleFetchFinishedAndResumeWaitingRequests(ModuleLoadRequest *
 }
 
 RefPtr<GenericPromise>
-ScriptLoader::WaitForModuleFetch(ModuleLoadRequest *aRequest)
+nsScriptLoader::WaitForModuleFetch(nsModuleLoadRequest *aRequest)
 {
   MOZ_ASSERT(ModuleMapContainsModule(aRequest));
 
@@ -819,7 +818,7 @@ ScriptLoader::WaitForModuleFetch(ModuleLoadRequest *aRequest)
     return promise;
   }
 
-  RefPtr<ModuleScript> ms;
+  RefPtr<nsModuleScript> ms;
   MOZ_ALWAYS_TRUE(mFetchedModules.Get(aRequest->mURI, getter_AddRefs(ms)));
   if (!ms || ms->InstantiationFailed()) {
     return GenericPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
@@ -828,17 +827,17 @@ ScriptLoader::WaitForModuleFetch(ModuleLoadRequest *aRequest)
   return GenericPromise::CreateAndResolve(true, __func__);
 }
 
-ModuleScript*
-ScriptLoader::GetFetchedModule(nsIURI* aURL) const
+nsModuleScript*
+nsScriptLoader::GetFetchedModule(nsIURI* aURL) const
 {
   bool found;
-  ModuleScript* ms = mFetchedModules.GetWeak(aURL, &found);
+  nsModuleScript* ms = mFetchedModules.GetWeak(aURL, &found);
   MOZ_ASSERT(found);
   return ms;
 }
 
 nsresult
-ScriptLoader::ProcessFetchedModuleSource(ModuleLoadRequest* aRequest)
+nsScriptLoader::ProcessFetchedModuleSource(nsModuleLoadRequest* aRequest)
 {
   MOZ_ASSERT(!aRequest->mModuleScript);
 
@@ -855,7 +854,7 @@ ScriptLoader::ProcessFetchedModuleSource(ModuleLoadRequest* aRequest)
 }
 
 nsresult
-ScriptLoader::CreateModuleScript(ModuleLoadRequest* aRequest)
+nsScriptLoader::CreateModuleScript(nsModuleLoadRequest* aRequest)
 {
   MOZ_ASSERT(!aRequest->mModuleScript);
   MOZ_ASSERT(aRequest->mBaseURL);
@@ -909,7 +908,7 @@ ScriptLoader::CreateModuleScript(ModuleLoadRequest* aRequest)
     MOZ_ASSERT(NS_SUCCEEDED(rv) == (module != nullptr));
     if (module) {
       aRequest->mModuleScript =
-        new ModuleScript(this, aRequest->mBaseURL, module);
+        new nsModuleScript(this, aRequest->mBaseURL, module);
     }
   }
 
@@ -919,7 +918,7 @@ ScriptLoader::CreateModuleScript(ModuleLoadRequest* aRequest)
 }
 
 static bool
-ThrowTypeError(JSContext* aCx, ModuleScript* aScript,
+ThrowTypeError(JSContext* aCx, nsModuleScript* aScript,
                const nsString& aMessage)
 {
   JS::Rooted<JSObject*> module(aCx, aScript->ModuleRecord());
@@ -946,7 +945,7 @@ ThrowTypeError(JSContext* aCx, ModuleScript* aScript,
 }
 
 static bool
-HandleResolveFailure(JSContext* aCx, ModuleScript* aScript,
+HandleResolveFailure(JSContext* aCx, nsModuleScript* aScript,
                      const nsAString& aSpecifier)
 {
   // TODO: How can we get the line number of the failed import?
@@ -958,7 +957,7 @@ HandleResolveFailure(JSContext* aCx, ModuleScript* aScript,
 }
 
 static bool
-HandleModuleNotFound(JSContext* aCx, ModuleScript* aScript,
+HandleModuleNotFound(JSContext* aCx, nsModuleScript* aScript,
                      const nsAString& aSpecifier)
 {
   // TODO: How can we get the line number of the failed import?
@@ -970,7 +969,7 @@ HandleModuleNotFound(JSContext* aCx, ModuleScript* aScript,
 }
 
 static already_AddRefed<nsIURI>
-ResolveModuleSpecifier(ModuleScript* aScript,
+ResolveModuleSpecifier(nsModuleScript* aScript,
                        const nsAString& aSpecifier)
 {
   // The following module specifiers are allowed by the spec:
@@ -1005,7 +1004,7 @@ ResolveModuleSpecifier(ModuleScript* aScript,
 }
 
 static nsresult
-RequestedModuleIsInAncestorList(ModuleLoadRequest* aRequest, nsIURI* aURL, bool* aResult)
+RequestedModuleIsInAncestorList(nsModuleLoadRequest* aRequest, nsIURI* aURL, bool* aResult)
 {
   const size_t ImportDepthLimit = 100;
 
@@ -1031,9 +1030,9 @@ RequestedModuleIsInAncestorList(ModuleLoadRequest* aRequest, nsIURI* aURL, bool*
 }
 
 static nsresult
-ResolveRequestedModules(ModuleLoadRequest* aRequest, nsCOMArray<nsIURI> &aUrls)
+ResolveRequestedModules(nsModuleLoadRequest* aRequest, nsCOMArray<nsIURI> &aUrls)
 {
-  ModuleScript* ms = aRequest->mModuleScript;
+  nsModuleScript* ms = aRequest->mModuleScript;
 
   AutoJSAPI jsapi;
   if (!jsapi.Init(ms->ModuleRecord())) {
@@ -1061,7 +1060,7 @@ ResolveRequestedModules(ModuleLoadRequest* aRequest, nsCOMArray<nsIURI> &aUrls)
     }
 
     // Let url be the result of resolving a module specifier given module script and requested.
-    ModuleScript* ms = aRequest->mModuleScript;
+    nsModuleScript* ms = aRequest->mModuleScript;
     nsCOMPtr<nsIURI> uri = ResolveModuleSpecifier(ms, specifier);
     if (!uri) {
       HandleResolveFailure(cx, ms, specifier);
@@ -1080,12 +1079,12 @@ ResolveRequestedModules(ModuleLoadRequest* aRequest, nsCOMArray<nsIURI> &aUrls)
 }
 
 void
-ScriptLoader::StartFetchingModuleDependencies(ModuleLoadRequest* aRequest)
+nsScriptLoader::StartFetchingModuleDependencies(nsModuleLoadRequest* aRequest)
 {
   MOZ_ASSERT(aRequest->mModuleScript);
   MOZ_ASSERT(!aRequest->mModuleScript->InstantiationFailed());
   MOZ_ASSERT(!aRequest->IsReadyToRun());
-  aRequest->mProgress = ModuleLoadRequest::Progress::FetchingImports;
+  aRequest->mProgress = nsModuleLoadRequest::Progress::FetchingImports;
 
   nsCOMArray<nsIURI> urls;
   nsresult rv = ResolveRequestedModules(aRequest, urls);
@@ -1113,18 +1112,18 @@ ScriptLoader::StartFetchingModuleDependencies(ModuleLoadRequest* aRequest)
   RefPtr<GenericPromise::AllPromiseType> allReady =
     GenericPromise::All(AbstractThread::GetCurrent(), importsReady);
   allReady->Then(AbstractThread::GetCurrent(), __func__, aRequest,
-                 &ModuleLoadRequest::DependenciesLoaded,
-                 &ModuleLoadRequest::LoadFailed);
+                 &nsModuleLoadRequest::DependenciesLoaded,
+                 &nsModuleLoadRequest::LoadFailed);
 }
 
 RefPtr<GenericPromise>
-ScriptLoader::StartFetchingModuleAndDependencies(ModuleLoadRequest* aRequest,
-                                                 nsIURI* aURI)
+nsScriptLoader::StartFetchingModuleAndDependencies(nsModuleLoadRequest* aRequest,
+                                                   nsIURI* aURI)
 {
   MOZ_ASSERT(aURI);
 
-  RefPtr<ModuleLoadRequest> childRequest =
-    new ModuleLoadRequest(aRequest->mElement, aRequest->mJSVersion,
+  RefPtr<nsModuleLoadRequest> childRequest =
+    new nsModuleLoadRequest(aRequest->mElement, aRequest->mJSVersion,
                             aRequest->mCORSMode, aRequest->mIntegrity, this);
 
   childRequest->mIsTopLevel = false;
@@ -1155,7 +1154,7 @@ HostResolveImportedModule(JSContext* aCx, unsigned argc, JS::Value* vp)
 
   // Let referencing module script be referencingModule.[[HostDefined]].
   JS::Value value = JS::GetModuleHostDefinedField(module);
-  auto script = static_cast<ModuleScript*>(value.toPrivate());
+  auto script = static_cast<nsModuleScript*>(value.toPrivate());
   MOZ_ASSERT(script->ModuleRecord() == module);
 
   // Let url be the result of resolving a module specifier given referencing
@@ -1174,7 +1173,7 @@ HostResolveImportedModule(JSContext* aCx, unsigned argc, JS::Value* vp)
   // Let resolved module script be the value of the entry in module map whose
   // key is url. If no such entry exists, throw a TypeError exception and abort
   // these steps.
-  ModuleScript* ms = script->Loader()->GetFetchedModule(uri);
+  nsModuleScript* ms = script->Loader()->GetFetchedModule(uri);
   if (!ms) {
     return HandleModuleNotFound(aCx, script, string);
   }
@@ -1208,7 +1207,7 @@ EnsureModuleResolveHook(JSContext* aCx)
 }
 
 void
-ScriptLoader::ProcessLoadedModuleTree(ModuleLoadRequest* aRequest)
+nsScriptLoader::ProcessLoadedModuleTree(nsModuleLoadRequest* aRequest)
 {
   if (aRequest->IsTopLevel()) {
     MaybeMoveToLoadedList(aRequest);
@@ -1221,13 +1220,13 @@ ScriptLoader::ProcessLoadedModuleTree(ModuleLoadRequest* aRequest)
 }
 
 bool
-ScriptLoader::InstantiateModuleTree(ModuleLoadRequest* aRequest)
+nsScriptLoader::InstantiateModuleTree(nsModuleLoadRequest* aRequest)
 {
   // Perform eager instantiation of the loaded module tree.
 
   MOZ_ASSERT(aRequest);
 
-  ModuleScript* ms = aRequest->mModuleScript;
+  nsModuleScript* ms = aRequest->mModuleScript;
   MOZ_ASSERT(ms);
   if (!ms->ModuleRecord()) {
     return false;
@@ -1256,14 +1255,14 @@ ScriptLoader::InstantiateModuleTree(ModuleLoadRequest* aRequest)
   // Mark this module and any uninstantiated dependencies found via depth-first
   // search as instantiated and record any error.
 
-  mozilla::Vector<ModuleLoadRequest*, 1> requests;
+  mozilla::Vector<nsModuleLoadRequest*, 1> requests;
   if (!requests.append(aRequest)) {
     return false;
   }
 
   while (!requests.empty()) {
-    ModuleLoadRequest* request = requests.popCopy();
-    ModuleScript* ms = request->mModuleScript;
+    nsModuleLoadRequest* request = requests.popCopy();
+    nsModuleScript* ms = request->mModuleScript;
     if (!ms->IsUninstantiated()) {
       continue;
     }
@@ -1297,7 +1296,7 @@ IsBytecodeCacheEnabled()
 }
 
 nsresult
-ScriptLoader::RestartLoad(ScriptLoadRequest *aRequest)
+nsScriptLoader::RestartLoad(nsScriptLoadRequest *aRequest)
 {
   MOZ_ASSERT(aRequest->IsBytecode());
   aRequest->mScriptBytecode.clearAndFree();
@@ -1305,7 +1304,7 @@ ScriptLoader::RestartLoad(ScriptLoadRequest *aRequest)
 
   // Start a new channel from which we explicitly request to stream the source
   // instead of the bytecode.
-  aRequest->mProgress = ScriptLoadRequest::Progress::Loading_Source;
+  aRequest->mProgress = nsScriptLoadRequest::Progress::Loading_Source;
   nsresult rv = StartLoad(aRequest);
   if (NS_FAILED(rv)) {
     return rv;
@@ -1317,11 +1316,11 @@ ScriptLoader::RestartLoad(ScriptLoadRequest *aRequest)
 }
 
 nsresult
-ScriptLoader::StartLoad(ScriptLoadRequest *aRequest)
+nsScriptLoader::StartLoad(nsScriptLoadRequest *aRequest)
 {
   MOZ_ASSERT(aRequest->IsLoading());
   NS_ENSURE_TRUE(mDocument, NS_ERROR_NULL_POINTER);
-  aRequest->mDataType = ScriptLoadRequest::DataType::Unknown;
+  aRequest->mDataType = nsScriptLoadRequest::DataType::Unknown;
 
   // If this document is sandboxed without 'allow-scripts', abort.
   if (mDocument->HasScriptsBlockedBySandbox()) {
@@ -1331,12 +1330,12 @@ ScriptLoader::StartLoad(ScriptLoadRequest *aRequest)
   if (aRequest->IsModuleRequest()) {
     // Check whether the module has been fetched or is currently being fetched,
     // and if so wait for it.
-    ModuleLoadRequest* request = aRequest->AsModuleRequest();
+    nsModuleLoadRequest* request = aRequest->AsModuleRequest();
     if (ModuleMapContainsModule(request)) {
       WaitForModuleFetch(request)
         ->Then(AbstractThread::GetCurrent(), __func__, request,
-               &ModuleLoadRequest::ModuleLoaded,
-               &ModuleLoadRequest::LoadFailed);
+               &nsModuleLoadRequest::ModuleLoaded,
+               &nsModuleLoadRequest::LoadFailed);
       return NS_OK;
     }
 
@@ -1474,8 +1473,8 @@ ScriptLoader::StartLoad(ScriptLoadRequest *aRequest)
                                                mReporter);
   }
 
-  RefPtr<ScriptLoadHandler> handler =
-      new ScriptLoadHandler(this, aRequest, sriDataVerifier.forget());
+  RefPtr<nsScriptLoadHandler> handler =
+      new nsScriptLoadHandler(this, aRequest, sriDataVerifier.forget());
 
   nsCOMPtr<nsIIncrementalStreamLoader> loader;
   rv = NS_NewIncrementalStreamLoader(getter_AddRefs(loader), handler);
@@ -1485,22 +1484,22 @@ ScriptLoader::StartLoad(ScriptLoadRequest *aRequest)
 }
 
 bool
-ScriptLoader::PreloadURIComparator::Equals(const PreloadInfo &aPi,
-                                           nsIURI * const &aURI) const
+nsScriptLoader::PreloadURIComparator::Equals(const PreloadInfo &aPi,
+                                             nsIURI * const &aURI) const
 {
   bool same;
   return NS_SUCCEEDED(aPi.mRequest->mURI->Equals(aURI, &same)) &&
          same;
 }
 
-class ScriptRequestProcessor : public Runnable
+class nsScriptRequestProcessor : public Runnable
 {
 private:
-  RefPtr<ScriptLoader> mLoader;
-  RefPtr<ScriptLoadRequest> mRequest;
+  RefPtr<nsScriptLoader> mLoader;
+  RefPtr<nsScriptLoadRequest> mRequest;
 public:
-  ScriptRequestProcessor(ScriptLoader* aLoader,
-                         ScriptLoadRequest* aRequest)
+  nsScriptRequestProcessor(nsScriptLoader* aLoader,
+                           nsScriptLoadRequest* aRequest)
     : mLoader(aLoader)
     , mRequest(aRequest)
   {}
@@ -1572,23 +1571,24 @@ CSPAllowsInlineScript(nsIScriptElement *aElement, nsIDocument *aDocument)
   return allowInlineScript;
 }
 
-ScriptLoadRequest*
-ScriptLoader::CreateLoadRequest(ScriptKind aKind,
-                                nsIScriptElement* aElement,
-                                uint32_t aVersion, CORSMode aCORSMode,
-                                const SRIMetadata &aIntegrity)
+nsScriptLoadRequest*
+nsScriptLoader::CreateLoadRequest(nsScriptKind aKind,
+                                  nsIScriptElement* aElement,
+                                  uint32_t aVersion, CORSMode aCORSMode,
+                                  const SRIMetadata &aIntegrity)
 {
-  if (aKind == ScriptKind::Classic) {
-    return new ScriptLoadRequest(aKind, aElement, aVersion, aCORSMode,
-                                 aIntegrity);
+  if (aKind == nsScriptKind::Classic) {
+    return new nsScriptLoadRequest(aKind, aElement, aVersion, aCORSMode,
+                                   aIntegrity);
   }
 
-  MOZ_ASSERT(aKind == ScriptKind::Module);
-  return new ModuleLoadRequest(aElement, aVersion, aCORSMode, aIntegrity, this);
+  MOZ_ASSERT(aKind == nsScriptKind::Module);
+  return new nsModuleLoadRequest(aElement, aVersion, aCORSMode, aIntegrity,
+                                 this);
 }
 
 bool
-ScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
+nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
 {
   // We need a document to evaluate scripts.
   NS_ENSURE_TRUE(mDocument, false);
@@ -1614,10 +1614,10 @@ ScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
   nsAutoString type;
   bool hasType = aElement->GetScriptType(type);
 
-  ScriptKind scriptKind = ScriptKind::Classic;
+  nsScriptKind scriptKind = nsScriptKind::Classic;
   if (!type.IsEmpty()) {
     if (ModuleScriptsEnabled() && type.LowerCaseEqualsASCII("module")) {
-      scriptKind = ScriptKind::Module;
+      scriptKind = nsScriptKind::Module;
     } else {
       NS_ENSURE_TRUE(ParseTypeAttribute(type, &version), false);
     }
@@ -1641,7 +1641,7 @@ ScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
   // "The nomodule attribute must not be specified on module scripts (and will
   // be ignored if it is)."
   if (ModuleScriptsEnabled() &&
-      scriptKind == ScriptKind::Classic &&
+      scriptKind == nsScriptKind::Classic &&
       scriptContent->IsHTMLElement() &&
       scriptContent->HasAttr(kNameSpaceID_None, nsGkAtoms::nomodule)) {
     return false;
@@ -1649,7 +1649,7 @@ ScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
 
   // Step 15. and later in the HTML5 spec
   nsresult rv = NS_OK;
-  RefPtr<ScriptLoadRequest> request;
+  RefPtr<nsScriptLoadRequest> request;
   if (aElement->GetScriptExternal()) {
     // external script
     nsCOMPtr<nsIURI> scriptURI = aElement->GetScriptURI();
@@ -1705,7 +1705,7 @@ ScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
                                integrity);
         if (!integrity.IsEmpty()) {
           MOZ_LOG(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug,
-                  ("ScriptLoader::ProcessScriptElement, integrity=%s",
+                  ("nsScriptLoader::ProcessScriptElement, integrity=%s",
                    NS_ConvertUTF16toUTF8(integrity).get()));
           nsAutoCString sourceUri;
           if (mDocument->GetDocumentURI()) {
@@ -1863,12 +1863,12 @@ ScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
   request->mIsInline = true;
   request->mURI = mDocument->GetDocumentURI();
   request->mLineNo = aElement->GetScriptLineNumber();
-  request->mProgress = ScriptLoadRequest::Progress::Loading_Source;
-  request->mDataType = ScriptLoadRequest::DataType::Source;
+  request->mProgress = nsScriptLoadRequest::Progress::Loading_Source;
+  request->mDataType = nsScriptLoadRequest::DataType::Source;
   TRACE_FOR_TEST_BOOL(request->mElement, "scriptloader_load_source");
 
   if (request->IsModuleRequest()) {
-    ModuleLoadRequest* modReq = request->AsModuleRequest();
+    nsModuleLoadRequest* modReq = request->AsModuleRequest();
     modReq->mBaseURL = mDocument->GetDocBaseURI();
     rv = CreateModuleScript(modReq);
     NS_ENSURE_SUCCESS(rv, false);
@@ -1880,7 +1880,7 @@ ScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
     }
     return false;
   }
-  request->mProgress = ScriptLoadRequest::Progress::Ready;
+  request->mProgress = nsScriptLoadRequest::Progress::Ready;
   if (aElement->GetParserCreated() == FROM_PARSER_XSLT &&
       (!ReadyToExecuteParserBlockingScripts() || !mXSLTRequests.isEmpty())) {
     // Need to maintain order for XSLT-inserted scripts
@@ -1892,7 +1892,7 @@ ScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
   if (aElement->GetParserCreated() == NOT_FROM_PARSER) {
     NS_ASSERTION(!nsContentUtils::IsSafeToRunScript(),
         "A script-inserted script is inserted without an update batch?");
-    nsContentUtils::AddScriptRunner(new ScriptRequestProcessor(this,
+    nsContentUtils::AddScriptRunner(new nsScriptRequestProcessor(this,
                                                                  request));
     return false;
   }
@@ -1922,14 +1922,14 @@ namespace {
 
 class NotifyOffThreadScriptLoadCompletedRunnable : public Runnable
 {
-  RefPtr<ScriptLoadRequest> mRequest;
-  RefPtr<ScriptLoader> mLoader;
+  RefPtr<nsScriptLoadRequest> mRequest;
+  RefPtr<nsScriptLoader> mLoader;
   RefPtr<DocGroup> mDocGroup;
   void *mToken;
 
 public:
-  NotifyOffThreadScriptLoadCompletedRunnable(ScriptLoadRequest* aRequest,
-                                             ScriptLoader* aLoader)
+  NotifyOffThreadScriptLoadCompletedRunnable(nsScriptLoadRequest* aRequest,
+                                             nsScriptLoader* aLoader)
     : mRequest(aRequest)
     , mLoader(aLoader)
     , mDocGroup(aLoader->GetDocGroup())
@@ -1958,16 +1958,16 @@ public:
 } /* anonymous namespace */
 
 nsresult
-ScriptLoader::ProcessOffThreadRequest(ScriptLoadRequest* aRequest)
+nsScriptLoader::ProcessOffThreadRequest(nsScriptLoadRequest* aRequest)
 {
-  MOZ_ASSERT(aRequest->mProgress == ScriptLoadRequest::Progress::Compiling);
+  MOZ_ASSERT(aRequest->mProgress == nsScriptLoadRequest::Progress::Compiling);
   MOZ_ASSERT(!aRequest->mWasCompiledOMT);
 
   aRequest->mWasCompiledOMT = true;
 
   if (aRequest->IsModuleRequest()) {
     MOZ_ASSERT(aRequest->mOffThreadToken);
-    ModuleLoadRequest* request = aRequest->AsModuleRequest();
+    nsModuleLoadRequest* request = aRequest->AsModuleRequest();
     nsresult rv = ProcessFetchedModuleSource(request);
     if (NS_FAILED(rv)) {
       request->LoadFailed();
@@ -2014,8 +2014,8 @@ NotifyOffThreadScriptLoadCompletedRunnable::Run()
 
   // We want these to be dropped on the main thread, once we return from this
   // function.
-  RefPtr<ScriptLoadRequest> request = mRequest.forget();
-  RefPtr<ScriptLoader> loader = mLoader.forget();
+  RefPtr<nsScriptLoadRequest> request = mRequest.forget();
+  RefPtr<nsScriptLoader> loader = mLoader.forget();
 
   request->mOffThreadToken = mToken;
   nsresult rv = loader->ProcessOffThreadRequest(request);
@@ -2033,7 +2033,7 @@ OffThreadScriptLoaderCallback(void *aToken, void *aCallbackData)
 }
 
 nsresult
-ScriptLoader::AttemptAsyncScriptCompile(ScriptLoadRequest* aRequest)
+nsScriptLoader::AttemptAsyncScriptCompile(nsScriptLoadRequest* aRequest)
 {
   MOZ_ASSERT_IF(!aRequest->IsModuleRequest(), aRequest->IsReadyToRun());
   MOZ_ASSERT(!aRequest->mWasCompiledOMT);
@@ -2103,15 +2103,15 @@ ScriptLoader::AttemptAsyncScriptCompile(ScriptLoadRequest* aRequest)
   mDocument->BlockOnload();
 
   // Once the compilation is finished, an event would be added to the event loop
-  // to call ScriptLoader::ProcessOffThreadRequest with the same request.
-  aRequest->mProgress = ScriptLoadRequest::Progress::Compiling;
+  // to call nsScriptLoader::ProcessOffThreadRequest with the same request.
+  aRequest->mProgress = nsScriptLoadRequest::Progress::Compiling;
 
   Unused << runnable.forget();
   return NS_OK;
 }
 
 nsresult
-ScriptLoader::CompileOffThreadOrProcessRequest(ScriptLoadRequest* aRequest)
+nsScriptLoader::CompileOffThreadOrProcessRequest(nsScriptLoadRequest* aRequest)
 {
   NS_ASSERTION(nsContentUtils::IsSafeToRunScript(),
                "Processing requests when running scripts is unsafe.");
@@ -2129,7 +2129,7 @@ ScriptLoader::CompileOffThreadOrProcessRequest(ScriptLoadRequest* aRequest)
 }
 
 SourceBufferHolder
-ScriptLoader::GetScriptSource(ScriptLoadRequest* aRequest, nsAutoString& inlineData)
+nsScriptLoader::GetScriptSource(nsScriptLoadRequest* aRequest, nsAutoString& inlineData)
 {
   // Return a SourceBufferHolder object holding the script's source text.
   // |inlineData| is used to hold the text for inline objects.
@@ -2150,7 +2150,7 @@ ScriptLoader::GetScriptSource(ScriptLoadRequest* aRequest, nsAutoString& inlineD
 }
 
 nsresult
-ScriptLoader::ProcessRequest(ScriptLoadRequest* aRequest)
+nsScriptLoader::ProcessRequest(nsScriptLoadRequest* aRequest)
 {
   NS_ASSERTION(nsContentUtils::IsSafeToRunScript(),
                "Processing requests when running scripts is unsafe.");
@@ -2249,8 +2249,8 @@ ScriptLoader::ProcessRequest(ScriptLoadRequest* aRequest)
 }
 
 void
-ScriptLoader::FireScriptAvailable(nsresult aResult,
-                                  ScriptLoadRequest* aRequest)
+nsScriptLoader::FireScriptAvailable(nsresult aResult,
+                                    nsScriptLoadRequest* aRequest)
 {
   for (int32_t i = 0; i < mObservers.Count(); i++) {
     nsCOMPtr<nsIScriptLoaderObserver> obs = mObservers[i];
@@ -2263,8 +2263,8 @@ ScriptLoader::FireScriptAvailable(nsresult aResult,
 }
 
 void
-ScriptLoader::FireScriptEvaluated(nsresult aResult,
-                                  ScriptLoadRequest* aRequest)
+nsScriptLoader::FireScriptEvaluated(nsresult aResult,
+                                    nsScriptLoadRequest* aRequest)
 {
   for (int32_t i = 0; i < mObservers.Count(); i++) {
     nsCOMPtr<nsIScriptLoaderObserver> obs = mObservers[i];
@@ -2276,7 +2276,7 @@ ScriptLoader::FireScriptEvaluated(nsresult aResult,
 }
 
 already_AddRefed<nsIScriptGlobalObject>
-ScriptLoader::GetScriptGlobalObject()
+nsScriptLoader::GetScriptGlobalObject()
 {
   nsCOMPtr<nsIDocument> master = mDocument->MasterDocument();
   nsPIDOMWindowInner *pwin = master->GetInnerWindow();
@@ -2297,10 +2297,10 @@ ScriptLoader::GetScriptGlobalObject()
 }
 
 nsresult
-ScriptLoader::FillCompileOptionsForRequest(const AutoJSAPI&jsapi,
-                                           ScriptLoadRequest* aRequest,
-                                           JS::Handle<JSObject*> aScopeChain,
-                                           JS::CompileOptions* aOptions)
+nsScriptLoader::FillCompileOptionsForRequest(const AutoJSAPI&jsapi,
+                                             nsScriptLoadRequest* aRequest,
+                                             JS::Handle<JSObject*> aScopeChain,
+                                             JS::CompileOptions* aOptions)
 {
   // It's very important to use aRequest->mURI, not the final URI of the channel
   // aRequest ended up getting script data from, as the script filename.
@@ -2362,7 +2362,7 @@ ScriptLoader::FillCompileOptionsForRequest(const AutoJSAPI&jsapi,
 }
 
 nsresult
-ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest)
+nsScriptLoader::EvaluateScript(nsScriptLoadRequest* aRequest)
 {
   MOZ_ASSERT(aRequest->IsReadyToRun());
 
@@ -2429,10 +2429,10 @@ ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest)
       // mDataType of the request might remain set to DataType::Unknown.
       MOZ_ASSERT(!aRequest->IsBytecode());
       LOG(("ScriptLoadRequest (%p): Evaluate Module", aRequest));
-      ModuleLoadRequest* request = aRequest->AsModuleRequest();
+      nsModuleLoadRequest* request = aRequest->AsModuleRequest();
       MOZ_ASSERT(request->mModuleScript);
       MOZ_ASSERT(!request->mOffThreadToken);
-      ModuleScript* ms = request->mModuleScript;
+      nsModuleScript* ms = request->mModuleScript;
       MOZ_ASSERT(!ms->IsUninstantiated());
       if (ms->InstantiationFailed()) {
         JS::Rooted<JS::Value> exception(aes.cx(), ms->Exception());
@@ -2523,7 +2523,7 @@ ScriptLoader::EvaluateScript(ScriptLoadRequest* aRequest)
 }
 
 void
-ScriptLoader::RegisterForBytecodeEncoding(ScriptLoadRequest* aRequest)
+nsScriptLoader::RegisterForBytecodeEncoding(nsScriptLoadRequest* aRequest)
 {
   MOZ_ASSERT(aRequest->mCacheInfo);
   MOZ_ASSERT(aRequest->mScript);
@@ -2531,14 +2531,14 @@ ScriptLoader::RegisterForBytecodeEncoding(ScriptLoadRequest* aRequest)
 }
 
 void
-ScriptLoader::LoadEventFired()
+nsScriptLoader::LoadEventFired()
 {
   mLoadEventFired = true;
   MaybeTriggerBytecodeEncoding();
 }
 
 void
-ScriptLoader::MaybeTriggerBytecodeEncoding()
+nsScriptLoader::MaybeTriggerBytecodeEncoding()
 {
   // We wait for the load event to be fired before saving the bytecode of
   // any script to the cache. It is quite common to have load event
@@ -2563,15 +2563,15 @@ ScriptLoader::MaybeTriggerBytecodeEncoding()
   // of all enqueued scripts. In case of failure, we give-up on encoding the
   // bytecode.
   nsCOMPtr<nsIRunnable> encoder =
-    NewRunnableMethod("ScriptLoader::EncodeBytecode",
-                      this, &ScriptLoader::EncodeBytecode);
+    NewRunnableMethod("nsScriptLoader::EncodeBytecode",
+                      this, &nsScriptLoader::EncodeBytecode);
   if (NS_FAILED(NS_DispatchToCurrentThread(encoder))) {
     GiveUpBytecodeEncoding();
   }
 }
 
 void
-ScriptLoader::EncodeBytecode()
+nsScriptLoader::EncodeBytecode()
 {
   // If any script got added in the previous loop cycle, wait until all
   // remaining script executions are completed, such that we capture most of
@@ -2593,7 +2593,7 @@ ScriptLoader::EncodeBytecode()
   }
 
   AutoEntryScript aes(globalObject, "encode bytecode", true);
-  RefPtr<ScriptLoadRequest> request;
+  RefPtr<nsScriptLoadRequest> request;
   while (!mBytecodeEncodingQueue.isEmpty()) {
     request = mBytecodeEncodingQueue.StealFirst();
     EncodeRequestBytecode(aes.cx(), request);
@@ -2603,7 +2603,7 @@ ScriptLoader::EncodeBytecode()
 }
 
 void
-ScriptLoader::EncodeRequestBytecode(JSContext* aCx, ScriptLoadRequest* aRequest)
+nsScriptLoader::EncodeRequestBytecode(JSContext* aCx, nsScriptLoadRequest* aRequest)
 {
   nsresult rv = NS_OK;
   MOZ_ASSERT(aRequest->mCacheInfo);
@@ -2656,7 +2656,7 @@ ScriptLoader::EncodeRequestBytecode(JSContext* aCx, ScriptLoadRequest* aRequest)
 }
 
 void
-ScriptLoadRequest::DropBytecodeCacheReferences()
+nsScriptLoadRequest::DropBytecodeCacheReferences()
 {
   mCacheInfo = nullptr;
   mScript = nullptr;
@@ -2664,7 +2664,7 @@ ScriptLoadRequest::DropBytecodeCacheReferences()
 }
 
 void
-ScriptLoader::GiveUpBytecodeEncoding()
+nsScriptLoader::GiveUpBytecodeEncoding()
 {
   // Ideally we prefer to properly end the incremental encoder, such that we
   // would not keep a large buffer around.  If we cannot, we fallback on the
@@ -2676,7 +2676,7 @@ ScriptLoader::GiveUpBytecodeEncoding()
       AutoEntryScript aes(globalObject, "give-up bytecode encoding", true);
       JS::RootedScript script(aes.cx());
       while (!mBytecodeEncodingQueue.isEmpty()) {
-        RefPtr<ScriptLoadRequest> request = mBytecodeEncodingQueue.StealFirst();
+        RefPtr<nsScriptLoadRequest> request = mBytecodeEncodingQueue.StealFirst();
         LOG(("ScriptLoadRequest (%p): Cannot serialize bytecode", request.get()));
         TRACE_FOR_TEST_NONE(request->mElement, "scriptloader_bytecode_failed");
         script.set(request->mScript);
@@ -2689,7 +2689,7 @@ ScriptLoader::GiveUpBytecodeEncoding()
   }
 
   while (!mBytecodeEncodingQueue.isEmpty()) {
-    RefPtr<ScriptLoadRequest> request = mBytecodeEncodingQueue.StealFirst();
+    RefPtr<nsScriptLoadRequest> request = mBytecodeEncodingQueue.StealFirst();
     LOG(("ScriptLoadRequest (%p): Cannot serialize bytecode", request.get()));
     TRACE_FOR_TEST_NONE(request->mElement, "scriptloader_bytecode_failed");
     // Note: Do not clear the mScriptBytecode buffer, because the incremental
@@ -2701,7 +2701,7 @@ ScriptLoader::GiveUpBytecodeEncoding()
 }
 
 bool
-ScriptLoader::HasPendingRequests()
+nsScriptLoader::HasPendingRequests()
 {
   return mParserBlockingRequest ||
          !mXSLTRequests.isEmpty() ||
@@ -2712,11 +2712,11 @@ ScriptLoader::HasPendingRequests()
 }
 
 void
-ScriptLoader::ProcessPendingRequestsAsync()
+nsScriptLoader::ProcessPendingRequestsAsync()
 {
   if (HasPendingRequests()) {
     nsCOMPtr<nsIRunnable> task = NewRunnableMethod(this,
-                                                   &ScriptLoader::ProcessPendingRequests);
+                                                   &nsScriptLoader::ProcessPendingRequests);
     if (mDocument) {
       mDocument->Dispatch("ScriptLoader", TaskCategory::Other, task.forget());
     } else {
@@ -2726,9 +2726,9 @@ ScriptLoader::ProcessPendingRequestsAsync()
 }
 
 void
-ScriptLoader::ProcessPendingRequests()
+nsScriptLoader::ProcessPendingRequests()
 {
-  RefPtr<ScriptLoadRequest> request;
+  RefPtr<nsScriptLoadRequest> request;
 
   if (mParserBlockingRequest &&
       mParserBlockingRequest->IsReadyToRun() &&
@@ -2780,7 +2780,7 @@ ScriptLoader::ProcessPendingRequests()
 
   while (!mPendingChildLoaders.IsEmpty() &&
          ReadyToExecuteParserBlockingScripts()) {
-    RefPtr<ScriptLoader> child = mPendingChildLoaders[0];
+    RefPtr<nsScriptLoader> child = mPendingChildLoaders[0];
     mPendingChildLoaders.RemoveElementAt(0);
     child->RemoveParserBlockingScriptExecutionBlocker();
   }
@@ -2806,7 +2806,7 @@ ScriptLoader::ProcessPendingRequests()
 }
 
 bool
-ScriptLoader::ReadyToExecuteParserBlockingScripts()
+nsScriptLoader::ReadyToExecuteParserBlockingScripts()
 {
   // Make sure the SelfReadyToExecuteParserBlockingScripts check is first, so
   // that we don't block twice on an ancestor.
@@ -2815,7 +2815,7 @@ ScriptLoader::ReadyToExecuteParserBlockingScripts()
   }
 
   for (nsIDocument* doc = mDocument; doc; doc = doc->GetParentDocument()) {
-    ScriptLoader* ancestor = doc->ScriptLoader();
+    nsScriptLoader* ancestor = doc->ScriptLoader();
     if (!ancestor->SelfReadyToExecuteParserBlockingScripts() &&
         ancestor->AddPendingChildLoader(this)) {
       AddParserBlockingScriptExecutionBlocker();
@@ -2863,10 +2863,10 @@ ScriptLoader::ReadyToExecuteParserBlockingScripts()
 }
 
 /* static */ nsresult
-ScriptLoader::ConvertToUTF16(nsIChannel* aChannel, const uint8_t* aData,
-                             uint32_t aLength, const nsAString& aHintCharset,
-                             nsIDocument* aDocument,
-                             char16_t*& aBufOut, size_t& aLengthOut)
+nsScriptLoader::ConvertToUTF16(nsIChannel* aChannel, const uint8_t* aData,
+                               uint32_t aLength, const nsAString& aHintCharset,
+                               nsIDocument* aDocument,
+                               char16_t*& aBufOut, size_t& aLengthOut)
 {
   if (!aLength) {
     aBufOut = nullptr;
@@ -2949,11 +2949,11 @@ ScriptLoader::ConvertToUTF16(nsIChannel* aChannel, const uint8_t* aData,
 }
 
 nsresult
-ScriptLoader::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
-                               ScriptLoadRequest* aRequest,
-                               nsresult aChannelStatus,
-                               nsresult aSRIStatus,
-                               mozilla::dom::SRICheckDataVerifier* aSRIDataVerifier)
+nsScriptLoader::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
+                                 nsScriptLoadRequest* aRequest,
+                                 nsresult aChannelStatus,
+                                 nsresult aSRIStatus,
+                                 mozilla::dom::SRICheckDataVerifier* aSRIDataVerifier)
 {
   NS_ASSERTION(aRequest, "null request in stream complete handler");
   NS_ENSURE_TRUE(aRequest, NS_ERROR_FAILURE);
@@ -2989,7 +2989,7 @@ ScriptLoader::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
 
     if (loadInfo && loadInfo->GetEnforceSRI()) {
       MOZ_LOG(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug,
-              ("ScriptLoader::OnStreamComplete, required SRI not found"));
+              ("nsScriptLoader::OnStreamComplete, required SRI not found"));
       nsCOMPtr<nsIContentSecurityPolicy> csp;
       loadInfo->LoadingPrincipal()->GetCsp(getter_AddRefs(csp));
       nsAutoCString violationURISpec;
@@ -3088,29 +3088,29 @@ ScriptLoader::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
       MOZ_ASSERT_IF(aRequest->IsModuleRequest(),
                     aRequest->AsModuleRequest()->IsTopLevel());
       if (aRequest->isInList()) {
-        RefPtr<ScriptLoadRequest> req = mDeferRequests.Steal(aRequest);
+        RefPtr<nsScriptLoadRequest> req = mDeferRequests.Steal(aRequest);
         FireScriptAvailable(rv, req);
       }
     } else if (aRequest->mIsAsync) {
       MOZ_ASSERT_IF(aRequest->IsModuleRequest(),
                     aRequest->AsModuleRequest()->IsTopLevel());
       if (aRequest->isInList()) {
-        RefPtr<ScriptLoadRequest> req = mLoadingAsyncRequests.Steal(aRequest);
+        RefPtr<nsScriptLoadRequest> req = mLoadingAsyncRequests.Steal(aRequest);
         FireScriptAvailable(rv, req);
       }
     } else if (aRequest->mIsNonAsyncScriptInserted) {
       if (aRequest->isInList()) {
-        RefPtr<ScriptLoadRequest> req =
+        RefPtr<nsScriptLoadRequest> req =
           mNonAsyncExternalScriptInsertedRequests.Steal(aRequest);
         FireScriptAvailable(rv, req);
       }
     } else if (aRequest->mIsXSLT) {
       if (aRequest->isInList()) {
-        RefPtr<ScriptLoadRequest> req = mXSLTRequests.Steal(aRequest);
+        RefPtr<nsScriptLoadRequest> req = mXSLTRequests.Steal(aRequest);
         FireScriptAvailable(rv, req);
       }
     } else if (aRequest->IsModuleRequest()) {
-      ModuleLoadRequest* modReq = aRequest->AsModuleRequest();
+      nsModuleLoadRequest* modReq = aRequest->AsModuleRequest();
       MOZ_ASSERT(!modReq->IsTopLevel());
       MOZ_ASSERT(!modReq->isInList());
       modReq->Cancel();
@@ -3141,19 +3141,19 @@ ScriptLoader::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
 }
 
 void
-ScriptLoader::UnblockParser(ScriptLoadRequest* aParserBlockingRequest)
+nsScriptLoader::UnblockParser(nsScriptLoadRequest* aParserBlockingRequest)
 {
   aParserBlockingRequest->mElement->UnblockParser();
 }
 
 void
-ScriptLoader::ContinueParserAsync(ScriptLoadRequest* aParserBlockingRequest)
+nsScriptLoader::ContinueParserAsync(nsScriptLoadRequest* aParserBlockingRequest)
 {
   aParserBlockingRequest->mElement->ContinueParserAsync();
 }
 
 uint32_t
-ScriptLoader::NumberOfProcessors()
+nsScriptLoader::NumberOfProcessors()
 {
   if (mNumberOfProcessors > 0)
     return mNumberOfProcessors;
@@ -3165,7 +3165,7 @@ ScriptLoader::NumberOfProcessors()
 }
 
 void
-ScriptLoader::MaybeMoveToLoadedList(ScriptLoadRequest* aRequest)
+nsScriptLoader::MaybeMoveToLoadedList(nsScriptLoadRequest* aRequest)
 {
   MOZ_ASSERT(aRequest->IsReadyToRun());
 
@@ -3175,16 +3175,16 @@ ScriptLoader::MaybeMoveToLoadedList(ScriptLoadRequest* aRequest)
   if (aRequest->mIsAsync) {
     MOZ_ASSERT(aRequest->isInList());
     if (aRequest->isInList()) {
-      RefPtr<ScriptLoadRequest> req = mLoadingAsyncRequests.Steal(aRequest);
+      RefPtr<nsScriptLoadRequest> req = mLoadingAsyncRequests.Steal(aRequest);
       mLoadedAsyncRequests.AppendElement(req);
     }
   }
 }
 
 nsresult
-ScriptLoader::PrepareLoadedRequest(ScriptLoadRequest* aRequest,
-                                   nsIIncrementalStreamLoader* aLoader,
-                                   nsresult aStatus)
+nsScriptLoader::PrepareLoadedRequest(nsScriptLoadRequest* aRequest,
+                                     nsIIncrementalStreamLoader* aLoader,
+                                     nsresult aStatus)
 {
   if (NS_FAILED(aStatus)) {
     return aStatus;
@@ -3254,7 +3254,7 @@ ScriptLoader::PrepareLoadedRequest(ScriptLoadRequest* aRequest,
 
   if (aRequest->IsModuleRequest()) {
     MOZ_ASSERT(aRequest->IsSource());
-    ModuleLoadRequest* request = aRequest->AsModuleRequest();
+    nsModuleLoadRequest* request = aRequest->AsModuleRequest();
 
     // When loading a module, only responses with a JavaScript MIME type are
     // acceptable.
@@ -3285,7 +3285,7 @@ ScriptLoader::PrepareLoadedRequest(ScriptLoadRequest* aRequest,
     MOZ_ASSERT(!aRequest->IsModuleRequest());
     nsresult rv = AttemptAsyncScriptCompile(aRequest);
     if (rv == NS_OK) {
-      MOZ_ASSERT(aRequest->mProgress == ScriptLoadRequest::Progress::Compiling,
+      MOZ_ASSERT(aRequest->mProgress == nsScriptLoadRequest::Progress::Compiling,
                  "Request should be off-thread compiling now.");
       return NS_OK;
     }
@@ -3304,7 +3304,7 @@ ScriptLoader::PrepareLoadedRequest(ScriptLoadRequest* aRequest,
 }
 
 void
-ScriptLoader::ParsingComplete(bool aTerminated)
+nsScriptLoader::ParsingComplete(bool aTerminated)
 {
   if (mDeferEnabled) {
     // Have to check because we apparently get ParsingComplete
@@ -3330,12 +3330,12 @@ ScriptLoader::ParsingComplete(bool aTerminated)
 }
 
 void
-ScriptLoader::PreloadURI(nsIURI *aURI, const nsAString &aCharset,
-                         const nsAString &aType,
-                         const nsAString &aCrossOrigin,
-                         const nsAString& aIntegrity,
-                         bool aScriptFromHead,
-                         const mozilla::net::ReferrerPolicy aReferrerPolicy)
+nsScriptLoader::PreloadURI(nsIURI *aURI, const nsAString &aCharset,
+                           const nsAString &aType,
+                           const nsAString &aCrossOrigin,
+                           const nsAString& aIntegrity,
+                           bool aScriptFromHead,
+                           const mozilla::net::ReferrerPolicy aReferrerPolicy)
 {
   NS_ENSURE_TRUE_VOID(mDocument);
   // Check to see if scripts has been turned off.
@@ -3351,7 +3351,7 @@ ScriptLoader::PreloadURI(nsIURI *aURI, const nsAString &aCharset,
   SRIMetadata sriMetadata;
   if (!aIntegrity.IsEmpty()) {
     MOZ_LOG(SRILogHelper::GetSriLog(), mozilla::LogLevel::Debug,
-            ("ScriptLoader::PreloadURI, integrity=%s",
+            ("nsScriptLoader::PreloadURI, integrity=%s",
              NS_ConvertUTF16toUTF8(aIntegrity).get()));
     nsAutoCString sourceUri;
     if (mDocument->GetDocumentURI()) {
@@ -3360,8 +3360,8 @@ ScriptLoader::PreloadURI(nsIURI *aURI, const nsAString &aCharset,
     SRICheck::IntegrityMetadata(aIntegrity, sourceUri, mReporter, &sriMetadata);
   }
 
-  RefPtr<ScriptLoadRequest> request =
-    CreateLoadRequest(ScriptKind::Classic, nullptr, 0,
+  RefPtr<nsScriptLoadRequest> request =
+    CreateLoadRequest(nsScriptKind::Classic, nullptr, 0,
                       Element::StringToCORSMode(aCrossOrigin), sriMetadata);
   request->mURI = aURI;
   request->mIsInline = false;
@@ -3379,7 +3379,7 @@ ScriptLoader::PreloadURI(nsIURI *aURI, const nsAString &aCharset,
 }
 
 void
-ScriptLoader::AddDeferRequest(ScriptLoadRequest* aRequest)
+nsScriptLoader::AddDeferRequest(nsScriptLoadRequest* aRequest)
 {
   aRequest->mIsDefer = true;
   mDeferRequests.AppendElement(aRequest);
@@ -3392,7 +3392,7 @@ ScriptLoader::AddDeferRequest(ScriptLoadRequest* aRequest)
 }
 
 bool
-ScriptLoader::MaybeRemovedDeferRequests()
+nsScriptLoader::MaybeRemovedDeferRequests()
 {
   if (mDeferRequests.isEmpty() && mDocument &&
       mBlockingDOMContentLoaded) {
@@ -3404,12 +3404,12 @@ ScriptLoader::MaybeRemovedDeferRequests()
 }
 
 //////////////////////////////////////////////////////////////
-// ScriptLoadHandler
+// nsScriptLoadHandler
 //////////////////////////////////////////////////////////////
 
-ScriptLoadHandler::ScriptLoadHandler(ScriptLoader *aScriptLoader,
-                                     ScriptLoadRequest *aRequest,
-                                     mozilla::dom::SRICheckDataVerifier *aSRIDataVerifier)
+nsScriptLoadHandler::nsScriptLoadHandler(nsScriptLoader *aScriptLoader,
+                                         nsScriptLoadRequest *aRequest,
+                                         mozilla::dom::SRICheckDataVerifier *aSRIDataVerifier)
   : mScriptLoader(aScriptLoader),
     mRequest(aRequest),
     mSRIDataVerifier(aSRIDataVerifier),
@@ -3420,17 +3420,17 @@ ScriptLoadHandler::ScriptLoadHandler(ScriptLoader *aScriptLoader,
   MOZ_ASSERT(mRequest->IsLoading());
 }
 
-ScriptLoadHandler::~ScriptLoadHandler()
+nsScriptLoadHandler::~nsScriptLoadHandler()
 {}
 
-NS_IMPL_ISUPPORTS(ScriptLoadHandler, nsIIncrementalStreamLoaderObserver)
+NS_IMPL_ISUPPORTS(nsScriptLoadHandler, nsIIncrementalStreamLoaderObserver)
 
 NS_IMETHODIMP
-ScriptLoadHandler::OnIncrementalData(nsIIncrementalStreamLoader* aLoader,
-                                     nsISupports* aContext,
-                                     uint32_t aDataLength,
-                                     const uint8_t* aData,
-                                     uint32_t *aConsumedLength)
+nsScriptLoadHandler::OnIncrementalData(nsIIncrementalStreamLoader* aLoader,
+                                       nsISupports* aContext,
+                                       uint32_t aDataLength,
+                                       const uint8_t* aData,
+                                       uint32_t *aConsumedLength)
 {
   if (mRequest->IsCanceled()) {
     // If request cancelled, ignore any incoming data.
@@ -3480,9 +3480,9 @@ ScriptLoadHandler::OnIncrementalData(nsIIncrementalStreamLoader* aLoader,
 }
 
 nsresult
-ScriptLoadHandler::DecodeRawData(const uint8_t* aData,
-                                 uint32_t aDataLength,
-                                 bool aEndOfStream)
+nsScriptLoadHandler::DecodeRawData(const uint8_t* aData,
+                                   uint32_t aDataLength,
+                                   bool aEndOfStream)
 {
   int32_t srcLen = aDataLength;
   const char* src = reinterpret_cast<const char *>(aData);
@@ -3516,10 +3516,10 @@ ScriptLoadHandler::DecodeRawData(const uint8_t* aData,
 }
 
 bool
-ScriptLoadHandler::EnsureDecoder(nsIIncrementalStreamLoader *aLoader,
-                                 const uint8_t* aData,
-                                 uint32_t aDataLength,
-                                 bool aEndOfStream)
+nsScriptLoadHandler::EnsureDecoder(nsIIncrementalStreamLoader *aLoader,
+                                   const uint8_t* aData,
+                                   uint32_t aDataLength,
+                                   bool aEndOfStream)
 {
   // Check if decoder has already been created.
   if (mDecoder) {
@@ -3539,11 +3539,11 @@ ScriptLoadHandler::EnsureDecoder(nsIIncrementalStreamLoader *aLoader,
 }
 
 bool
-ScriptLoadHandler::EnsureDecoder(nsIIncrementalStreamLoader *aLoader,
-                                 const uint8_t* aData,
-                                 uint32_t aDataLength,
-                                 bool aEndOfStream,
-                                 nsCString& oCharset)
+nsScriptLoadHandler::EnsureDecoder(nsIIncrementalStreamLoader *aLoader,
+                                   const uint8_t* aData,
+                                   uint32_t aDataLength,
+                                   bool aEndOfStream,
+                                   nsCString& oCharset)
 {
   // JavaScript modules are always UTF-8.
   if (mRequest->IsModuleRequest()) {
@@ -3586,9 +3586,9 @@ ScriptLoadHandler::EnsureDecoder(nsIIncrementalStreamLoader *aLoader,
   if (!mRequest->IsPreload()) {
     mRequest->mElement->GetScriptCharset(hintCharset);
   } else {
-    nsTArray<ScriptLoader::PreloadInfo>::index_type i =
+    nsTArray<nsScriptLoader::PreloadInfo>::index_type i =
       mScriptLoader->mPreloads.IndexOf(mRequest, 0,
-            ScriptLoader::PreloadRequestComparator());
+            nsScriptLoader::PreloadRequestComparator());
 
     NS_ASSERTION(i != mScriptLoader->mPreloads.NoIndex,
                  "Incorrect preload bookkeeping");
@@ -3618,7 +3618,7 @@ ScriptLoadHandler::EnsureDecoder(nsIIncrementalStreamLoader *aLoader,
 }
 
 nsresult
-ScriptLoadHandler::MaybeDecodeSRI()
+nsScriptLoadHandler::MaybeDecodeSRI()
 {
   if (!mSRIDataVerifier || mSRIDataVerifier->IsComplete() || NS_FAILED(mSRIStatus)) {
     return NS_OK;
@@ -3635,7 +3635,7 @@ ScriptLoadHandler::MaybeDecodeSRI()
   if (NS_FAILED(mSRIStatus)) {
     // We are unable to decode the hash contained in the alternate data which
     // contains the bytecode, or it does not use the same algorithm.
-    LOG(("ScriptLoadHandler::MaybeDecodeSRI, failed to decode SRI, restart request"));
+    LOG(("nsScriptLoadHandler::MaybeDecodeSRI, failed to decode SRI, restart request"));
     return mSRIStatus;
   }
 
@@ -3644,12 +3644,12 @@ ScriptLoadHandler::MaybeDecodeSRI()
 }
 
 nsresult
-ScriptLoadHandler::EnsureKnownDataType(nsIIncrementalStreamLoader *aLoader)
+nsScriptLoadHandler::EnsureKnownDataType(nsIIncrementalStreamLoader *aLoader)
 {
   MOZ_ASSERT(mRequest->IsUnknownDataType());
   MOZ_ASSERT(mRequest->IsLoading());
   if (mRequest->IsLoadingSource()) {
-    mRequest->mDataType = ScriptLoadRequest::DataType::Source;
+    mRequest->mDataType = nsScriptLoadRequest::DataType::Source;
     TRACE_FOR_TEST(mRequest->mElement, "scriptloader_load_source");
     return NS_OK;
   }
@@ -3664,14 +3664,14 @@ ScriptLoadHandler::EnsureKnownDataType(nsIIncrementalStreamLoader *aLoader)
     nsAutoCString altDataType;
     cic->GetAlternativeDataType(altDataType);
     if (altDataType == kBytecodeMimeType) {
-      mRequest->mDataType = ScriptLoadRequest::DataType::Bytecode;
+      mRequest->mDataType = nsScriptLoadRequest::DataType::Bytecode;
       TRACE_FOR_TEST(mRequest->mElement, "scriptloader_load_bytecode");
     } else {
-      mRequest->mDataType = ScriptLoadRequest::DataType::Source;
+      mRequest->mDataType = nsScriptLoadRequest::DataType::Source;
       TRACE_FOR_TEST(mRequest->mElement, "scriptloader_load_source");
     }
   } else {
-    mRequest->mDataType = ScriptLoadRequest::DataType::Source;
+    mRequest->mDataType = nsScriptLoadRequest::DataType::Source;
     TRACE_FOR_TEST(mRequest->mElement, "scriptloader_load_source");
   }
   MOZ_ASSERT(!mRequest->IsUnknownDataType());
@@ -3680,11 +3680,11 @@ ScriptLoadHandler::EnsureKnownDataType(nsIIncrementalStreamLoader *aLoader)
 }
 
 NS_IMETHODIMP
-ScriptLoadHandler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
-                                    nsISupports* aContext,
-                                    nsresult aStatus,
-                                    uint32_t aDataLength,
-                                    const uint8_t* aData)
+nsScriptLoadHandler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
+                                      nsISupports* aContext,
+                                      nsresult aStatus,
+                                      uint32_t aDataLength,
+                                      const uint8_t* aData)
 {
   nsresult rv = NS_OK;
   if (LOG_ENABLED()) {
@@ -3728,7 +3728,7 @@ ScriptLoadHandler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
 
       // If we abort while decoding the SRI, we fallback on explictly requesting
       // the source. Thus, we should not continue in
-      // ScriptLoader::OnStreamComplete, which removes the request from the
+      // nsScriptLoader::OnStreamComplete, which removes the request from the
       // waiting lists.
       rv = MaybeDecodeSRI();
       if (NS_FAILED(rv)) {
@@ -3775,6 +3775,3 @@ ScriptLoadHandler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
 #undef LOG_WARN
 #undef LOG
 #undef LOG_VERBOSE
-
-} // dom namespace
-} // mozilla namespace
diff --git a/dom/script/ScriptLoader.h b/dom/base/nsScriptLoader.h
similarity index 80%
rename from dom/script/ScriptLoader.h
rename to dom/base/nsScriptLoader.h
index 61929f5ad034..672f143dbe4d 100644
--- a/dom/script/ScriptLoader.h
+++ b/dom/base/nsScriptLoader.h
@@ -8,8 +8,8 @@
  * A class that handles loading and evaluation of <script> elements.
  */
 
-#ifndef mozilla_dom_ScriptLoader_h
-#define mozilla_dom_ScriptLoader_h
+#ifndef __nsScriptLoader_h__
+#define __nsScriptLoader_h__
 
 #include "nsCOMPtr.h"
 #include "nsRefPtrHashtable.h"
@@ -31,6 +31,9 @@
 #include "mozilla/net/ReferrerPolicy.h"
 #include "mozilla/Vector.h"
 
+class nsModuleLoadRequest;
+class nsModuleScript;
+class nsScriptLoadRequestList;
 class nsIURI;
 
 namespace JS {
@@ -39,36 +42,34 @@ namespace JS {
 
 namespace mozilla {
 namespace dom {
-
 class AutoJSAPI;
-class ModuleLoadRequest;
-class ModuleScript;
-class ScriptLoadRequestList;
+} // namespace dom
+} // namespace mozilla
 
 //////////////////////////////////////////////////////////////
 // Per-request data structure
 //////////////////////////////////////////////////////////////
 
-enum class ScriptKind {
+enum class nsScriptKind {
   Classic,
   Module
 };
 
-class ScriptLoadRequest : public nsISupports,
-                          private mozilla::LinkedListElement<ScriptLoadRequest>
+class nsScriptLoadRequest : public nsISupports,
+                            private mozilla::LinkedListElement<nsScriptLoadRequest>
 {
-  typedef LinkedListElement<ScriptLoadRequest> super;
+  typedef LinkedListElement<nsScriptLoadRequest> super;
 
-  // Allow LinkedListElement<ScriptLoadRequest> to cast us to itself as needed.
-  friend class mozilla::LinkedListElement<ScriptLoadRequest>;
-  friend class ScriptLoadRequestList;
+  // Allow LinkedListElement<nsScriptLoadRequest> to cast us to itself as needed.
+  friend class mozilla::LinkedListElement<nsScriptLoadRequest>;
+  friend class nsScriptLoadRequestList;
 
 protected:
-  virtual ~ScriptLoadRequest();
+  virtual ~nsScriptLoadRequest();
 
 public:
-  ScriptLoadRequest(ScriptKind aKind,
-                    nsIScriptElement* aElement,
+  nsScriptLoadRequest(nsScriptKind aKind,
+                      nsIScriptElement* aElement,
                       uint32_t aVersion,
                       mozilla::CORSMode aCORSMode,
                       const mozilla::dom::SRIMetadata &aIntegrity)
@@ -99,14 +100,14 @@ public:
   }
 
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(ScriptLoadRequest)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsScriptLoadRequest)
 
   bool IsModuleRequest() const
   {
-    return mKind == ScriptKind::Module;
+    return mKind == nsScriptKind::Module;
   }
 
-  ModuleLoadRequest* AsModuleRequest();
+  nsModuleLoadRequest* AsModuleRequest();
 
   void FireScriptAvailable(nsresult aResult)
   {
@@ -192,7 +193,7 @@ public:
   using super::getNext;
   using super::isInList;
 
-  const ScriptKind mKind;
+  const nsScriptKind mKind;
   nsCOMPtr<nsIScriptElement> mElement;
   bool mScriptFromHead;   // Synchronous head script block loading of other non js/css content.
   Progress mProgress;     // Are we still waiting for a load to complete?
@@ -236,23 +237,23 @@ public:
   nsCOMPtr<nsICacheInfoChannel> mCacheInfo;
 };
 
-class ScriptLoadRequestList : private mozilla::LinkedList<ScriptLoadRequest>
+class nsScriptLoadRequestList : private mozilla::LinkedList<nsScriptLoadRequest>
 {
-  typedef mozilla::LinkedList<ScriptLoadRequest> super;
+  typedef mozilla::LinkedList<nsScriptLoadRequest> super;
 
 public:
-  ~ScriptLoadRequestList();
+  ~nsScriptLoadRequestList();
 
   void Clear();
 
 #ifdef DEBUG
-  bool Contains(ScriptLoadRequest* aElem) const;
+  bool Contains(nsScriptLoadRequest* aElem) const;
 #endif // DEBUG
 
   using super::getFirst;
   using super::isEmpty;
 
-  void AppendElement(ScriptLoadRequest* aElem)
+  void AppendElement(nsScriptLoadRequest* aElem)
   {
     MOZ_ASSERT(!aElem->isInList());
     NS_ADDREF(aElem);
@@ -260,20 +261,20 @@ public:
   }
 
   MOZ_MUST_USE
-  already_AddRefed<ScriptLoadRequest> Steal(ScriptLoadRequest* aElem)
+  already_AddRefed<nsScriptLoadRequest> Steal(nsScriptLoadRequest* aElem)
   {
     aElem->removeFrom(*this);
     return dont_AddRef(aElem);
   }
 
   MOZ_MUST_USE
-  already_AddRefed<ScriptLoadRequest> StealFirst()
+  already_AddRefed<nsScriptLoadRequest> StealFirst()
   {
     MOZ_ASSERT(!isEmpty());
     return Steal(getFirst());
   }
 
-  void Remove(ScriptLoadRequest* aElem)
+  void Remove(nsScriptLoadRequest* aElem)
   {
     aElem->removeFrom(*this);
     NS_RELEASE(aElem);
@@ -284,12 +285,12 @@ public:
 // Script loader implementation
 //////////////////////////////////////////////////////////////
 
-class ScriptLoader final : public nsISupports
+class nsScriptLoader final : public nsISupports
 {
   class MOZ_STACK_CLASS AutoCurrentScriptUpdater
   {
   public:
-    AutoCurrentScriptUpdater(ScriptLoader* aScriptLoader,
+    AutoCurrentScriptUpdater(nsScriptLoader* aScriptLoader,
                              nsIScriptElement* aCurrentScript)
       : mOldScript(aScriptLoader->mCurrentScript)
       , mScriptLoader(aScriptLoader)
@@ -302,19 +303,19 @@ class ScriptLoader final : public nsISupports
     }
   private:
     nsCOMPtr<nsIScriptElement> mOldScript;
-    ScriptLoader* mScriptLoader;
+    nsScriptLoader* mScriptLoader;
   };
 
-  friend class ModuleLoadRequest;
-  friend class ScriptRequestProcessor;
-  friend class ScriptLoadHandler;
+  friend class nsModuleLoadRequest;
+  friend class nsScriptRequestProcessor;
+  friend class nsScriptLoadHandler;
   friend class AutoCurrentScriptUpdater;
 
 public:
-  explicit ScriptLoader(nsIDocument* aDocument);
+  explicit nsScriptLoader(nsIDocument* aDocument);
 
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_CLASS(ScriptLoader)
+  NS_DECL_CYCLE_COLLECTION_CLASS(nsScriptLoader)
 
   /**
    * The loader maintains a weak reference to the document with
@@ -467,12 +468,12 @@ public:
 
   /**
    * Handle the completion of a stream.  This is called by the
-   * ScriptLoadHandler object which observes the IncrementalStreamLoader
+   * nsScriptLoadHandler object which observes the IncrementalStreamLoader
    * loading the script. The streamed content is expected to be stored on the
    * aRequest argument.
    */
   nsresult OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
-                            ScriptLoadRequest* aRequest,
+                            nsScriptLoadRequest* aRequest,
                             nsresult aChannelStatus,
                             nsresult aSRIStatus,
                             mozilla::dom::SRICheckDataVerifier* aSRIDataVerifier);
@@ -540,9 +541,9 @@ public:
    * Process a request that was deferred so that the script could be compiled
    * off thread.
    */
-  nsresult ProcessOffThreadRequest(ScriptLoadRequest *aRequest);
+  nsresult ProcessOffThreadRequest(nsScriptLoadRequest *aRequest);
 
-  bool AddPendingChildLoader(ScriptLoader* aChild) {
+  bool AddPendingChildLoader(nsScriptLoader* aChild) {
     return mPendingChildLoaders.AppendElement(aChild) != nullptr;
   }
 
@@ -559,10 +560,10 @@ public:
   void LoadEventFired();
 
 private:
-  virtual ~ScriptLoader();
+  virtual ~nsScriptLoader();
 
-  ScriptLoadRequest* CreateLoadRequest(
-    ScriptKind aKind,
+  nsScriptLoadRequest* CreateLoadRequest(
+    nsScriptKind aKind,
     nsIScriptElement* aElement,
     uint32_t aVersion,
     mozilla::CORSMode aCORSMode,
@@ -571,12 +572,12 @@ private:
   /**
    * Unblocks the creator parser of the parser-blocking scripts.
    */
-  void UnblockParser(ScriptLoadRequest* aParserBlockingRequest);
+  void UnblockParser(nsScriptLoadRequest* aParserBlockingRequest);
 
   /**
    * Asynchronously resumes the creator parser of the parser-blocking scripts.
    */
-  void ContinueParserAsync(ScriptLoadRequest* aParserBlockingRequest);
+  void ContinueParserAsync(nsScriptLoadRequest* aParserBlockingRequest);
 
 
   /**
@@ -591,14 +592,14 @@ private:
   /**
    * Start a load for aRequest's URI.
    */
-  nsresult StartLoad(ScriptLoadRequest *aRequest);
+  nsresult StartLoad(nsScriptLoadRequest *aRequest);
 
   /**
    * Abort the current stream, and re-start with a new load request from scratch
    * without requesting any alternate data. Returns NS_BINDING_RETARGETED on
    * success, as this error code is used to abort the input stream.
    */
-  nsresult RestartLoad(ScriptLoadRequest *aRequest);
+  nsresult RestartLoad(nsScriptLoadRequest *aRequest);
 
   /**
    * Process any pending requests asynchronously (i.e. off an event) if there
@@ -634,14 +635,14 @@ private:
     return mEnabled && !mBlockerCount;
   }
 
-  nsresult AttemptAsyncScriptCompile(ScriptLoadRequest* aRequest);
-  nsresult ProcessRequest(ScriptLoadRequest* aRequest);
-  nsresult CompileOffThreadOrProcessRequest(ScriptLoadRequest* aRequest);
+  nsresult AttemptAsyncScriptCompile(nsScriptLoadRequest* aRequest);
+  nsresult ProcessRequest(nsScriptLoadRequest* aRequest);
+  nsresult CompileOffThreadOrProcessRequest(nsScriptLoadRequest* aRequest);
   void FireScriptAvailable(nsresult aResult,
-                           ScriptLoadRequest* aRequest);
+                           nsScriptLoadRequest* aRequest);
   void FireScriptEvaluated(nsresult aResult,
-                           ScriptLoadRequest* aRequest);
-  nsresult EvaluateScript(ScriptLoadRequest* aRequest);
+                           nsScriptLoadRequest* aRequest);
+  nsresult EvaluateScript(nsScriptLoadRequest* aRequest);
 
   /**
    * Queue the current script load request to be saved, when the page
@@ -649,7 +650,7 @@ private:
    * time when the load event got received, and when no more scripts are waiting
    * to be executed.
    */
-  void RegisterForBytecodeEncoding(ScriptLoadRequest* aRequest);
+  void RegisterForBytecodeEncoding(nsScriptLoadRequest* aRequest);
 
   /**
    * Check if all conditions are met, i-e that the onLoad event fired and that
@@ -663,81 +664,81 @@ private:
    * functions on the cache provided by the channel.
    */
   void EncodeBytecode();
-  void EncodeRequestBytecode(JSContext* aCx, ScriptLoadRequest* aRequest);
+  void EncodeRequestBytecode(JSContext* aCx, nsScriptLoadRequest* aRequest);
 
   void GiveUpBytecodeEncoding();
 
   already_AddRefed<nsIScriptGlobalObject> GetScriptGlobalObject();
   nsresult FillCompileOptionsForRequest(const mozilla::dom::AutoJSAPI& jsapi,
-                                        ScriptLoadRequest* aRequest,
+                                        nsScriptLoadRequest* aRequest,
                                         JS::Handle<JSObject*> aScopeChain,
                                         JS::CompileOptions* aOptions);
 
   uint32_t NumberOfProcessors();
-  nsresult PrepareLoadedRequest(ScriptLoadRequest* aRequest,
+  nsresult PrepareLoadedRequest(nsScriptLoadRequest* aRequest,
                                 nsIIncrementalStreamLoader* aLoader,
                                 nsresult aStatus);
 
-  void AddDeferRequest(ScriptLoadRequest* aRequest);
+  void AddDeferRequest(nsScriptLoadRequest* aRequest);
   bool MaybeRemovedDeferRequests();
 
-  void MaybeMoveToLoadedList(ScriptLoadRequest* aRequest);
+  void MaybeMoveToLoadedList(nsScriptLoadRequest* aRequest);
 
-  JS::SourceBufferHolder GetScriptSource(ScriptLoadRequest* aRequest,
+  JS::SourceBufferHolder GetScriptSource(nsScriptLoadRequest* aRequest,
                                          nsAutoString& inlineData);
 
   bool ModuleScriptsEnabled();
 
-  void SetModuleFetchStarted(ModuleLoadRequest *aRequest);
-  void SetModuleFetchFinishedAndResumeWaitingRequests(ModuleLoadRequest *aRequest,
+  void SetModuleFetchStarted(nsModuleLoadRequest *aRequest);
+  void SetModuleFetchFinishedAndResumeWaitingRequests(nsModuleLoadRequest *aRequest,
                                                       nsresult aResult);
 
-  bool IsFetchingModule(ModuleLoadRequest *aRequest) const;
+  bool IsFetchingModule(nsModuleLoadRequest *aRequest) const;
 
-  bool ModuleMapContainsModule(ModuleLoadRequest *aRequest) const;
-  RefPtr<mozilla::GenericPromise> WaitForModuleFetch(ModuleLoadRequest *aRequest);
-  ModuleScript* GetFetchedModule(nsIURI* aURL) const;
+  bool ModuleMapContainsModule(nsModuleLoadRequest *aRequest) const;
+  RefPtr<mozilla::GenericPromise> WaitForModuleFetch(nsModuleLoadRequest *aRequest);
+  nsModuleScript* GetFetchedModule(nsIURI* aURL) const;
 
   friend bool
   HostResolveImportedModule(JSContext* aCx, unsigned argc, JS::Value* vp);
 
-  nsresult CreateModuleScript(ModuleLoadRequest* aRequest);
-  nsresult ProcessFetchedModuleSource(ModuleLoadRequest* aRequest);
-  void ProcessLoadedModuleTree(ModuleLoadRequest* aRequest);
-  bool InstantiateModuleTree(ModuleLoadRequest* aRequest);
-  void StartFetchingModuleDependencies(ModuleLoadRequest* aRequest);
+  nsresult CreateModuleScript(nsModuleLoadRequest* aRequest);
+  nsresult ProcessFetchedModuleSource(nsModuleLoadRequest* aRequest);
+  void ProcessLoadedModuleTree(nsModuleLoadRequest* aRequest);
+  bool InstantiateModuleTree(nsModuleLoadRequest* aRequest);
+  void StartFetchingModuleDependencies(nsModuleLoadRequest* aRequest);
 
   RefPtr<mozilla::GenericPromise>
-  StartFetchingModuleAndDependencies(ModuleLoadRequest* aRequest, nsIURI* aURI);
+  StartFetchingModuleAndDependencies(nsModuleLoadRequest* aRequest, nsIURI* aURI);
 
   nsIDocument* mDocument;                   // [WEAK]
   nsCOMArray<nsIScriptLoaderObserver> mObservers;
-  ScriptLoadRequestList mNonAsyncExternalScriptInsertedRequests;
+  nsScriptLoadRequestList mNonAsyncExternalScriptInsertedRequests;
   // mLoadingAsyncRequests holds async requests while they're loading; when they
   // have been loaded they are moved to mLoadedAsyncRequests.
-  ScriptLoadRequestList mLoadingAsyncRequests;
-  ScriptLoadRequestList mLoadedAsyncRequests;
-  ScriptLoadRequestList mDeferRequests;
-  ScriptLoadRequestList mXSLTRequests;
-  RefPtr<ScriptLoadRequest> mParserBlockingRequest;
+  nsScriptLoadRequestList mLoadingAsyncRequests;
+  nsScriptLoadRequestList mLoadedAsyncRequests;
+  nsScriptLoadRequestList mDeferRequests;
+  nsScriptLoadRequestList mXSLTRequests;
+  RefPtr<nsScriptLoadRequest> mParserBlockingRequest;
 
   // List of script load request that are holding a buffer which has to be saved
   // on the cache.
-  ScriptLoadRequestList mBytecodeEncodingQueue;
+  nsScriptLoadRequestList mBytecodeEncodingQueue;
 
   // In mRequests, the additional information here is stored by the element.
   struct PreloadInfo {
-    RefPtr<ScriptLoadRequest> mRequest;
+    RefPtr<nsScriptLoadRequest> mRequest;
     nsString mCharset;
   };
 
-  friend void ImplCycleCollectionUnlink(ScriptLoader::PreloadInfo& aField);
+  friend void ImplCycleCollectionUnlink(nsScriptLoader::PreloadInfo& aField);
   friend void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
-                                          ScriptLoader::PreloadInfo& aField,
+                                          nsScriptLoader::PreloadInfo& aField,
                                           const char* aName, uint32_t aFlags);
 
   struct PreloadRequestComparator {
-    bool Equals(const PreloadInfo &aPi, ScriptLoadRequest * const &aRequest)
+    bool Equals(const PreloadInfo &aPi, nsScriptLoadRequest * const &aRequest)
         const
     {
       return aRequest == aPi.mRequest;
@@ -750,7 +751,7 @@ private:
 
   nsCOMPtr<nsIScriptElement> mCurrentScript;
   nsCOMPtr<nsIScriptElement> mCurrentParserInsertedScript;
-  nsTArray< RefPtr<ScriptLoader> > mPendingChildLoaders;
+  nsTArray< RefPtr<nsScriptLoader> > mPendingChildLoaders;
   uint32_t mParserBlockingBlockerCount;
   uint32_t mBlockerCount;
   uint32_t mNumberOfProcessors;
@@ -762,23 +763,23 @@ private:
 
   // Module map
   nsRefPtrHashtable<nsURIHashKey, mozilla::GenericPromise::Private> mFetchingModules;
-  nsRefPtrHashtable<nsURIHashKey, ModuleScript> mFetchedModules;
+  nsRefPtrHashtable<nsURIHashKey, nsModuleScript> mFetchedModules;
 
   nsCOMPtr<nsIConsoleReportCollector> mReporter;
 };
 
-class ScriptLoadHandler final : public nsIIncrementalStreamLoaderObserver
+class nsScriptLoadHandler final : public nsIIncrementalStreamLoaderObserver
 {
 public:
-  explicit ScriptLoadHandler(ScriptLoader* aScriptLoader,
-                             ScriptLoadRequest *aRequest,
-                             mozilla::dom::SRICheckDataVerifier *aSRIDataVerifier);
+  explicit nsScriptLoadHandler(nsScriptLoader* aScriptLoader,
+                               nsScriptLoadRequest *aRequest,
+                               mozilla::dom::SRICheckDataVerifier *aSRIDataVerifier);
 
   NS_DECL_ISUPPORTS
   NS_DECL_NSIINCREMENTALSTREAMLOADEROBSERVER
 
 private:
-  virtual ~ScriptLoadHandler();
+  virtual ~nsScriptLoadHandler();
 
   /*
    * Once the charset is found by the EnsureDecoder function, we can
@@ -809,10 +810,10 @@ private:
   nsresult EnsureKnownDataType(nsIIncrementalStreamLoader *aLoader);
 
   // ScriptLoader which will handle the parsed script.
-  RefPtr<ScriptLoader>        mScriptLoader;
+  RefPtr<nsScriptLoader>        mScriptLoader;
 
-  // The ScriptLoadRequest for this load. Decoded data are accumulated on it.
-  RefPtr<ScriptLoadRequest>   mRequest;
+  // The nsScriptLoadRequest for this load. Decoded data are accumulated on it.
+  RefPtr<nsScriptLoadRequest>   mRequest;
 
   // SRI data verifier.
   nsAutoPtr<mozilla::dom::SRICheckDataVerifier> mSRIDataVerifier;
@@ -844,10 +845,7 @@ public:
   }
 
   bool mWasEnabled;
-  RefPtr<ScriptLoader> mLoader;
+  RefPtr<nsScriptLoader> mLoader;
 };
 
-} // namespace dom
-} // namespace mozilla
-
-#endif // mozilla_dom_ScriptLoader_h
+#endif //__nsScriptLoader_h__
diff --git a/dom/base/test/test_script_loader_js_cache.html b/dom/base/test/test_script_loader_js_cache.html
index e3f881109dbb..8ca2012f3943 100644
--- a/dom/base/test/test_script_loader_js_cache.html
+++ b/dom/base/test/test_script_loader_js_cache.html
@@ -2,7 +2,7 @@
 <html>
 <!-- https://bugzilla.mozilla.org/show_bug.cgi?id=900784 -->
 <!-- The JS bytecode cache is not supposed to be observable. To make it
-     observable, the ScriptLoader is instrumented to trigger events on the
+     observable, the nsScriptLoader is instrumented to trigger events on the
      script tag. These events are followed to reconstruct the code path taken by
      the script loader and associate a simple name which is checked in these
      test cases.
@@ -14,7 +14,7 @@
   <script src="/resources/testharnessreport.js"></script>
   <script type="application/javascript">
     // This is the state machine of the trace events produced by the
-    // ScriptLoader. This state machine is used to give a name to each
+    // nsScriptLoader. This state machine is used to give a name to each
     // code path, such that we can assert each code path with a single word.
     var scriptLoaderStateMachine = {
       "scriptloader_load_source": {
@@ -112,7 +112,7 @@
     promise_test(async function() {
       // Setting dom.expose_test_interfaces pref causes the
       // nsScriptLoadRequest to fire event on script tags, with information
-      // about its internal state. The ScriptLoader source send events to
+      // about its internal state. The nsScriptLoader source send events to
       // trace these and resolve a promise with the path taken by the
       // script loader.
       //
diff --git a/dom/console/Console.cpp b/dom/console/Console.cpp
index 375621bc925f..2364f46ebfe8 100644
--- a/dom/console/Console.cpp
+++ b/dom/console/Console.cpp
@@ -12,7 +12,6 @@
 #include "mozilla/dom/File.h"
 #include "mozilla/dom/FunctionBinding.h"
 #include "mozilla/dom/Performance.h"
-#include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/StructuredCloneHolder.h"
 #include "mozilla/dom/ToJSValue.h"
 #include "mozilla/dom/WorkletGlobalScope.h"
@@ -23,6 +22,7 @@
 #include "nsGlobalWindow.h"
 #include "nsJSUtils.h"
 #include "nsNetUtil.h"
+#include "ScriptSettings.h"
 #include "WorkerPrivate.h"
 #include "WorkerRunnable.h"
 #include "WorkerScope.h"
diff --git a/dom/events/DOMEventTargetHelper.cpp b/dom/events/DOMEventTargetHelper.cpp
index f30f9b74665b..8ed8720565a5 100644
--- a/dom/events/DOMEventTargetHelper.cpp
+++ b/dom/events/DOMEventTargetHelper.cpp
@@ -8,7 +8,7 @@
 #include "nsIDocument.h"
 #include "mozilla/Sprintf.h"
 #include "nsGlobalWindow.h"
-#include "mozilla/dom/ScriptSettings.h"
+#include "ScriptSettings.h"
 #include "mozilla/DOMEventTargetHelper.h"
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/EventListenerManager.h"
diff --git a/dom/html/HTMLScriptElement.cpp b/dom/html/HTMLScriptElement.cpp
index 0b5c065a316b..ef189ac661e5 100644
--- a/dom/html/HTMLScriptElement.cpp
+++ b/dom/html/HTMLScriptElement.cpp
@@ -38,7 +38,7 @@ HTMLScriptElement::WrapNode(JSContext *aCx, JS::Handle<JSObject*> aGivenProto)
 HTMLScriptElement::HTMLScriptElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo,
                                      FromParser aFromParser)
   : nsGenericHTMLElement(aNodeInfo)
-  , ScriptElement(aFromParser)
+  , nsScriptElement(aFromParser)
 {
   AddMutationObserver(this);
 }
diff --git a/dom/html/HTMLScriptElement.h b/dom/html/HTMLScriptElement.h
index d37370511c1b..f81d6ec00520 100644
--- a/dom/html/HTMLScriptElement.h
+++ b/dom/html/HTMLScriptElement.h
@@ -8,16 +8,16 @@
 #define mozilla_dom_HTMLScriptElement_h
 
 #include "nsIDOMHTMLScriptElement.h"
+#include "nsScriptElement.h"
 #include "nsGenericHTMLElement.h"
 #include "mozilla/Attributes.h"
-#include "mozilla/dom/ScriptElement.h"
 
 namespace mozilla {
 namespace dom {
 
 class HTMLScriptElement final : public nsGenericHTMLElement,
                                 public nsIDOMHTMLScriptElement,
-                                public ScriptElement
+                                public nsScriptElement
 {
 public:
   using Element::GetText;
@@ -97,8 +97,7 @@ protected:
   virtual ~HTMLScriptElement();
 
   virtual JSObject* WrapNode(JSContext *aCx, JS::Handle<JSObject*> aGivenProto) override;
-
-  // ScriptElement
+  // nsScriptElement
   virtual bool HasScriptContent() override;
 };
 
diff --git a/dom/html/nsGenericHTMLElement.cpp b/dom/html/nsGenericHTMLElement.cpp
index 359eba9d5842..d3e9a37abcf1 100644
--- a/dom/html/nsGenericHTMLElement.cpp
+++ b/dom/html/nsGenericHTMLElement.cpp
@@ -49,6 +49,7 @@
 #include "nsIDocShell.h"
 #include "nsNameSpaceManager.h"
 #include "nsError.h"
+#include "nsScriptLoader.h"
 #include "nsIPrincipal.h"
 #include "nsContainerFrame.h"
 #include "nsStyleUtil.h"
@@ -90,7 +91,6 @@
 #include "mozilla/dom/FromParser.h"
 #include "mozilla/dom/Link.h"
 #include "mozilla/BloomFilter.h"
-#include "mozilla/dom/ScriptLoader.h"
 
 #include "nsVariant.h"
 #include "nsDOMTokenList.h"
diff --git a/dom/html/nsHTMLContentSink.cpp b/dom/html/nsHTMLContentSink.cpp
index 2cce0acf037d..ad829d2dd845 100644
--- a/dom/html/nsHTMLContentSink.cpp
+++ b/dom/html/nsHTMLContentSink.cpp
@@ -19,10 +19,10 @@
 #include "nsIHTMLContentSink.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
+#include "nsScriptLoader.h"
 #include "nsIURI.h"
 #include "nsIContentViewer.h"
 #include "mozilla/dom/NodeInfo.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "nsToken.h"
 #include "nsIAppShell.h"
 #include "nsCRT.h"
diff --git a/dom/messagechannel/MessagePort.cpp b/dom/messagechannel/MessagePort.cpp
index 37d77b5f1b83..055dea294e6d 100644
--- a/dom/messagechannel/MessagePort.cpp
+++ b/dom/messagechannel/MessagePort.cpp
@@ -16,7 +16,6 @@
 #include "mozilla/dom/MessagePortBinding.h"
 #include "mozilla/dom/MessagePortChild.h"
 #include "mozilla/dom/PMessagePort.h"
-#include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/StructuredCloneTags.h"
 #include "mozilla/dom/WorkerPrivate.h"
 #include "mozilla/dom/WorkerScope.h"
@@ -29,6 +28,7 @@
 #include "nsContentUtils.h"
 #include "nsGlobalWindow.h"
 #include "nsPresContext.h"
+#include "ScriptSettings.h"
 #include "SharedMessagePortMessage.h"
 
 #include "nsIBFCacheEntry.h"
diff --git a/dom/moz.build b/dom/moz.build
index 4c2f05a5ada7..51b88e0d7172 100644
--- a/dom/moz.build
+++ b/dom/moz.build
@@ -104,7 +104,6 @@ DIRS += [
     'webbrowserpersist',
     'xhr',
     'worklet',
-    'script',
 ]
 
 if CONFIG['OS_ARCH'] == 'WINNT':
diff --git a/dom/script/moz.build b/dom/script/moz.build
deleted file mode 100644
index eba2de07f0ff..000000000000
--- a/dom/script/moz.build
+++ /dev/null
@@ -1,39 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-with Files("**"):
-    BUG_COMPONENT = ("Core", "DOM")
-
-XPIDL_SOURCES += [
-    'nsIScriptLoaderObserver.idl',
-]
-
-XPIDL_MODULE = 'dom'
-
-EXPORTS += [
-    'nsIScriptElement.h',
-]
-
-EXPORTS.mozilla.dom += [
-    'ScriptElement.h',
-    'ScriptLoader.h',
-    'ScriptSettings.h',
-]
-
-UNIFIED_SOURCES += [
-    'ScriptElement.cpp',
-    'ScriptLoader.cpp',
-    'ScriptSettings.cpp',
-]
-
-LOCAL_INCLUDES += [
-    '/dom/base',
-    '/dom/workers',
-]
-
-include('/ipc/chromium/chromium-config.mozbuild')
-
-FINAL_LIBRARY = 'xul'
diff --git a/dom/svg/SVGScriptElement.cpp b/dom/svg/SVGScriptElement.cpp
index fabc18a1a453..291c40005810 100644
--- a/dom/svg/SVGScriptElement.cpp
+++ b/dom/svg/SVGScriptElement.cpp
@@ -43,7 +43,7 @@ NS_IMPL_ISUPPORTS_INHERITED(SVGScriptElement, SVGScriptElementBase,
 SVGScriptElement::SVGScriptElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo,
                                    FromParser aFromParser)
   : SVGScriptElementBase(aNodeInfo)
-  , ScriptElement(aFromParser)
+  , nsScriptElement(aFromParser)
 {
   AddMutationObserver(this);
 }
@@ -190,7 +190,7 @@ SVGScriptElement::FreezeUriAsyncDefer()
 }
 
 //----------------------------------------------------------------------
-// ScriptElement methods
+// nsScriptElement methods
 
 bool
 SVGScriptElement::HasScriptContent()
diff --git a/dom/svg/SVGScriptElement.h b/dom/svg/SVGScriptElement.h
index 034250144061..b29788e68db2 100644
--- a/dom/svg/SVGScriptElement.h
+++ b/dom/svg/SVGScriptElement.h
@@ -10,7 +10,7 @@
 #include "nsSVGElement.h"
 #include "nsCOMPtr.h"
 #include "nsSVGString.h"
-#include "mozilla/dom/ScriptElement.h"
+#include "nsScriptElement.h"
 
 class nsIDocument;
 
@@ -24,7 +24,7 @@ namespace dom {
 typedef nsSVGElement SVGScriptElementBase;
 
 class SVGScriptElement final : public SVGScriptElementBase,
-                               public ScriptElement
+                               public nsScriptElement
 {
 protected:
   friend nsresult (::NS_NewSVGScriptElement(nsIContent **aResult,
@@ -47,7 +47,7 @@ public:
   virtual void FreezeUriAsyncDefer() override;
   virtual CORSMode GetCORSMode() const override;
 
-  // ScriptElement
+  // nsScriptElement
   virtual bool HasScriptContent() override;
 
   // nsIContent specializations:
diff --git a/dom/workers/ScriptLoader.cpp b/dom/workers/ScriptLoader.cpp
index 20db8e5ae0a3..120aefbbf519 100644
--- a/dom/workers/ScriptLoader.cpp
+++ b/dom/workers/ScriptLoader.cpp
@@ -34,6 +34,7 @@
 #include "nsIPipe.h"
 #include "nsIOutputStream.h"
 #include "nsPrintfCString.h"
+#include "nsScriptLoader.h"
 #include "nsString.h"
 #include "nsStreamUtils.h"
 #include "nsTArray.h"
@@ -57,7 +58,6 @@
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/PromiseNativeHandler.h"
 #include "mozilla/dom/Response.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/SRILogHelper.h"
 #include "mozilla/UniquePtr.h"
@@ -427,7 +427,7 @@ private:
 NS_IMPL_ISUPPORTS0(CacheCreator)
 
 class CacheScriptLoader final : public PromiseNativeHandler
-                              , public nsIStreamLoaderObserver
+                                  , public nsIStreamLoaderObserver
 {
 public:
   NS_DECL_ISUPPORTS
@@ -1078,14 +1078,14 @@ private:
     // May be null.
     nsIDocument* parentDoc = mWorkerPrivate->GetDocument();
 
-    // Use the regular ScriptLoader for this grunt work! Should be just fine
+    // Use the regular nsScriptLoader for this grunt work! Should be just fine
     // because we're running on the main thread.
     // Unlike <script> tags, Worker scripts are always decoded as UTF-8,
     // per spec. So we explicitly pass in the charset hint.
-    rv = ScriptLoader::ConvertToUTF16(aLoadInfo.mChannel, aString, aStringLen,
-                                      NS_LITERAL_STRING("UTF-8"), parentDoc,
-                                      aLoadInfo.mScriptTextBuf,
-                                      aLoadInfo.mScriptTextLength);
+    rv = nsScriptLoader::ConvertToUTF16(aLoadInfo.mChannel, aString, aStringLen,
+                                        NS_LITERAL_STRING("UTF-8"), parentDoc,
+                                        aLoadInfo.mScriptTextBuf,
+                                        aLoadInfo.mScriptTextLength);
     if (NS_FAILED(rv)) {
       return rv;
     }
@@ -1212,10 +1212,10 @@ private:
     MOZ_ASSERT(!loadInfo.mScriptTextBuf);
 
     nsresult rv =
-      ScriptLoader::ConvertToUTF16(nullptr, aString, aStringLen,
-                                   NS_LITERAL_STRING("UTF-8"), parentDoc,
-                                   loadInfo.mScriptTextBuf,
-                                   loadInfo.mScriptTextLength);
+      nsScriptLoader::ConvertToUTF16(nullptr, aString, aStringLen,
+                                     NS_LITERAL_STRING("UTF-8"), parentDoc,
+                                     loadInfo.mScriptTextBuf,
+                                     loadInfo.mScriptTextLength);
     if (NS_SUCCEEDED(rv) && IsMainWorkerScript()) {
       nsCOMPtr<nsIURI> finalURI;
       rv = NS_NewURI(getter_AddRefs(finalURI), loadInfo.mFullURL, nullptr, nullptr);
diff --git a/dom/workers/ServiceWorkerManager.cpp b/dom/workers/ServiceWorkerManager.cpp
index 8f92bc64a815..8c6034eecea1 100644
--- a/dom/workers/ServiceWorkerManager.cpp
+++ b/dom/workers/ServiceWorkerManager.cpp
@@ -22,6 +22,7 @@
 #include "nsITimer.h"
 #include "nsIUploadChannel2.h"
 #include "nsPIDOMWindow.h"
+#include "nsScriptLoader.h"
 #include "nsServiceManagerUtils.h"
 #include "nsDebug.h"
 #include "nsISupportsPrimitives.h"
@@ -50,7 +51,6 @@
 #include "mozilla/ipc/BackgroundChild.h"
 #include "mozilla/ipc/PBackgroundChild.h"
 #include "mozilla/ipc/PBackgroundSharedTypes.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/Unused.h"
 #include "mozilla/EnumSet.h"
 
diff --git a/dom/workers/ServiceWorkerScriptCache.cpp b/dom/workers/ServiceWorkerScriptCache.cpp
index 1f235e5e5a93..d97490fbfea9 100644
--- a/dom/workers/ServiceWorkerScriptCache.cpp
+++ b/dom/workers/ServiceWorkerScriptCache.cpp
@@ -11,7 +11,6 @@
 #include "mozilla/dom/cache/Cache.h"
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/PromiseWorkerProxy.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/ipc/BackgroundUtils.h"
 #include "mozilla/ipc/PBackgroundSharedTypes.h"
 #include "nsICacheInfoChannel.h"
@@ -24,6 +23,7 @@
 #include "nsIScriptSecurityManager.h"
 #include "nsContentUtils.h"
 #include "nsNetUtil.h"
+#include "nsScriptLoader.h"
 #include "ServiceWorkerManager.h"
 #include "Workers.h"
 #include "nsStringStream.h"
@@ -828,9 +828,9 @@ CompareNetwork::OnStreamComplete(nsIStreamLoader* aLoader, nsISupports* aContext
   char16_t* buffer = nullptr;
   size_t len = 0;
 
-  rv = ScriptLoader::ConvertToUTF16(httpChannel, aString, aLen,
-                                    NS_LITERAL_STRING("UTF-8"), nullptr,
-                                    buffer, len);
+  rv = nsScriptLoader::ConvertToUTF16(httpChannel, aString, aLen,
+                                      NS_LITERAL_STRING("UTF-8"), nullptr,
+                                      buffer, len);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     mManager->NetworkFinished(rv);
     return rv;
@@ -882,9 +882,9 @@ CompareCache::OnStreamComplete(nsIStreamLoader* aLoader, nsISupports* aContext,
   char16_t* buffer = nullptr;
   size_t len = 0;
 
-  nsresult rv = ScriptLoader::ConvertToUTF16(nullptr, aString, aLen,
-                                             NS_LITERAL_STRING("UTF-8"),
-                                             nullptr, buffer, len);
+  nsresult rv = nsScriptLoader::ConvertToUTF16(nullptr, aString, aLen,
+                                               NS_LITERAL_STRING("UTF-8"),
+                                               nullptr, buffer, len);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     mManager->CacheFinished(rv, false);
     return rv;
diff --git a/dom/worklet/Worklet.cpp b/dom/worklet/Worklet.cpp
index d71c36a24f45..77b8a9647ba6 100644
--- a/dom/worklet/Worklet.cpp
+++ b/dom/worklet/Worklet.cpp
@@ -15,9 +15,9 @@
 #include "mozilla/dom/RegisterWorkletBindings.h"
 #include "mozilla/dom/Response.h"
 #include "mozilla/dom/ScriptSettings.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "nsIThreadRetargetableRequest.h"
 #include "nsNetUtil.h"
+#include "nsScriptLoader.h"
 #include "xpcprivate.h"
 
 namespace mozilla {
@@ -174,9 +174,9 @@ public:
     char16_t* scriptTextBuf;
     size_t scriptTextLength;
     nsresult rv =
-      ScriptLoader::ConvertToUTF16(nullptr, aString, aStringLen,
-                                   NS_LITERAL_STRING("UTF-8"), nullptr,
-                                   scriptTextBuf, scriptTextLength);
+      nsScriptLoader::ConvertToUTF16(nullptr, aString, aStringLen,
+                                     NS_LITERAL_STRING("UTF-8"), nullptr,
+                                     scriptTextBuf, scriptTextLength);
     if (NS_WARN_IF(NS_FAILED(rv))) {
       RejectPromises(rv);
       return NS_OK;
diff --git a/dom/xml/nsXMLContentSink.cpp b/dom/xml/nsXMLContentSink.cpp
index 19b0cc8ee8ec..cbf13c914b11 100644
--- a/dom/xml/nsXMLContentSink.cpp
+++ b/dom/xml/nsXMLContentSink.cpp
@@ -35,6 +35,7 @@
 #include "nsRect.h"
 #include "nsIWebNavigation.h"
 #include "nsIScriptElement.h"
+#include "nsScriptLoader.h"
 #include "nsStyleLinkElement.h"
 #include "nsReadableUtils.h"
 #include "nsUnicharUtils.h"
@@ -61,7 +62,6 @@
 #include "mozilla/dom/Element.h"
 #include "mozilla/dom/HTMLTemplateElement.h"
 #include "mozilla/dom/ProcessingInstruction.h"
-#include "mozilla/dom/ScriptLoader.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
diff --git a/dom/xml/nsXMLFragmentContentSink.cpp b/dom/xml/nsXMLFragmentContentSink.cpp
index a516f6b69aa3..16f03160a845 100644
--- a/dom/xml/nsXMLFragmentContentSink.cpp
+++ b/dom/xml/nsXMLFragmentContentSink.cpp
@@ -25,10 +25,10 @@
 #include "nsTArray.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsIDocShell.h"
+#include "nsScriptLoader.h"
 #include "mozilla/css/Loader.h"
 #include "mozilla/dom/DocumentFragment.h"
 #include "mozilla/dom/ProcessingInstruction.h"
-#include "mozilla/dom/ScriptLoader.h"
 
 using namespace mozilla::dom;
 
diff --git a/dom/xslt/xslt/txMozillaXMLOutput.cpp b/dom/xslt/xslt/txMozillaXMLOutput.cpp
index 1e93a6648ac3..c128251d2bbb 100644
--- a/dom/xslt/xslt/txMozillaXMLOutput.cpp
+++ b/dom/xslt/xslt/txMozillaXMLOutput.cpp
@@ -7,6 +7,7 @@
 
 #include "nsIDocument.h"
 #include "nsIDocShell.h"
+#include "nsScriptLoader.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMDocumentType.h"
 #include "nsIScriptElement.h"
@@ -30,7 +31,6 @@
 #include "mozilla/css/Loader.h"
 #include "mozilla/dom/Element.h"
 #include "mozilla/dom/EncodingUtils.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "nsContentUtils.h"
 #include "txXMLUtils.h"
 #include "nsContentSink.h"
@@ -230,7 +230,7 @@ txMozillaXMLOutput::endDocument(nsresult aResult)
         MOZ_ASSERT(mDocument->GetReadyStateEnum() ==
                    nsIDocument::READYSTATE_LOADING, "Bad readyState");
         mDocument->SetReadyStateInternal(nsIDocument::READYSTATE_INTERACTIVE);
-        ScriptLoader* loader = mDocument->ScriptLoader();
+        nsScriptLoader* loader = mDocument->ScriptLoader();
         if (loader) {
             loader->ParsingComplete(false);
         }
@@ -419,7 +419,7 @@ txMozillaXMLOutput::startDocument()
     }
 
     if (mCreatingNewDocument) {
-        ScriptLoader* loader = mDocument->ScriptLoader();
+        nsScriptLoader* loader = mDocument->ScriptLoader();
         if (loader) {
             loader->BeginDeferringScripts();
         }
@@ -860,7 +860,7 @@ txMozillaXMLOutput::createResultDocument(const nsSubstring& aName, int32_t aNsID
     }
 
     // Set up script loader of the result document.
-    ScriptLoader *loader = mDocument->ScriptLoader();
+    nsScriptLoader *loader = mDocument->ScriptLoader();
     if (mNotifier) {
         loader->AddObserver(mNotifier);
     }
diff --git a/dom/xul/XULDocument.cpp b/dom/xul/XULDocument.cpp
index 8ab4e40c1ef5..2398abf8f093 100644
--- a/dom/xul/XULDocument.cpp
+++ b/dom/xul/XULDocument.cpp
@@ -3344,10 +3344,10 @@ XULDocument::OnStreamComplete(nsIStreamLoader* aLoader,
                                             !mOffThreadCompileStringBuf),
                    "XULDocument can't load multiple scripts at once");
 
-        rv = ScriptLoader::ConvertToUTF16(channel, string, stringLen,
-                                          EmptyString(), this,
-                                          mOffThreadCompileStringBuf,
-                                          mOffThreadCompileStringLength);
+        rv = nsScriptLoader::ConvertToUTF16(channel, string, stringLen,
+                                            EmptyString(), this,
+                                            mOffThreadCompileStringBuf,
+                                            mOffThreadCompileStringLength);
         if (NS_SUCCEEDED(rv)) {
             // Attempt to give ownership of the buffer to the JS engine.  If
             // we hit offthread compilation, however, we will have to take it
diff --git a/dom/xul/XULDocument.h b/dom/xul/XULDocument.h
index 6455818a71e6..b529721aa844 100644
--- a/dom/xul/XULDocument.h
+++ b/dom/xul/XULDocument.h
@@ -21,13 +21,13 @@
 #include "nsCOMArray.h"
 #include "nsIURI.h"
 #include "nsIXULDocument.h"
+#include "nsScriptLoader.h"
 #include "nsIStreamListener.h"
 #include "nsIStreamLoader.h"
 #include "nsICSSLoaderObserver.h"
 #include "nsIXULStore.h"
 
 #include "mozilla/Attributes.h"
-#include "mozilla/dom/ScriptLoader.h"
 
 #include "js/TracingAPI.h"
 #include "js/TypeDecls.h"
diff --git a/dom/xul/nsXULContentSink.cpp b/dom/xul/nsXULContentSink.cpp
index cd2b875901bd..7103be758d91 100644
--- a/dom/xul/nsXULContentSink.cpp
+++ b/dom/xul/nsXULContentSink.cpp
@@ -879,7 +879,7 @@ XULContentSinkImpl::OpenScript(const char16_t** aAttributes,
               isJavaScript = false;
           }
       } else if (key.EqualsLiteral("language")) {
-          // Language is deprecated, and the impl in ScriptLoader ignores the
+          // Language is deprecated, and the impl in nsScriptLoader ignores the
           // various version strings anyway.  So we make no attempt to support
           // languages other than JS for language=
           nsAutoString lang(aAttributes[1]);
diff --git a/js/xpconnect/loader/ChromeScriptLoader.cpp b/js/xpconnect/loader/ChromeScriptLoader.cpp
index 6bda60fee844..fa4b6960cfb3 100644
--- a/js/xpconnect/loader/ChromeScriptLoader.cpp
+++ b/js/xpconnect/loader/ChromeScriptLoader.cpp
@@ -9,6 +9,7 @@
 #include "nsIURI.h"
 #include "nsIChannel.h"
 #include "nsNetUtil.h"
+#include "nsScriptLoader.h"
 #include "nsThreadUtils.h"
 
 #include "jsapi.h"
@@ -17,7 +18,6 @@
 
 #include "mozilla/dom/ChromeUtils.h"
 #include "mozilla/dom/Promise.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/HoldDropJSObjects.h"
 #include "mozilla/SystemGroup.h"
 #include "nsCycleCollectionParticipant.h"
@@ -241,7 +241,7 @@ AsyncScriptCompiler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
         return NS_OK;
     }
 
-    nsresult rv = ScriptLoader::ConvertToUTF16(
+    nsresult rv = nsScriptLoader::ConvertToUTF16(
         nullptr, aBuf, aLength, mCharset, nullptr, mScriptText, mScriptLength);
     if (NS_FAILED(rv)) {
         Reject(cx, "Unable to decode script");
diff --git a/js/xpconnect/loader/mozJSSubScriptLoader.cpp b/js/xpconnect/loader/mozJSSubScriptLoader.cpp
index 967f7671ee2e..a84d47bbf26b 100644
--- a/js/xpconnect/loader/mozJSSubScriptLoader.cpp
+++ b/js/xpconnect/loader/mozJSSubScriptLoader.cpp
@@ -15,6 +15,7 @@
 #include "nsNetCID.h"
 #include "nsNetUtil.h"
 #include "nsIFileURL.h"
+#include "nsScriptLoader.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsThreadUtils.h"
 
@@ -26,7 +27,6 @@
 
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/ToJSValue.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/HoldDropJSObjects.h"
 #include "mozilla/ScriptPreloader.h"
 #include "mozilla/scache/StartupCache.h"
@@ -148,8 +148,8 @@ PrepareScript(nsIURI* uri,
         size_t scriptLength = 0;
 
         nsresult rv =
-            ScriptLoader::ConvertToUTF16(nullptr, reinterpret_cast<const uint8_t*>(buf), len,
-                                         charset, nullptr, scriptBuf, scriptLength);
+            nsScriptLoader::ConvertToUTF16(nullptr, reinterpret_cast<const uint8_t*>(buf), len,
+                                           charset, nullptr, scriptBuf, scriptLength);
 
         JS::SourceBufferHolder srcBuf(scriptBuf, scriptLength,
                                       JS::SourceBufferHolder::GiveOwnership);
@@ -858,9 +858,9 @@ ScriptPrecompiler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
     // Convert data to char16_t* and prepare to call CompileOffThread.
     nsAutoString hintCharset;
     nsresult rv =
-        ScriptLoader::ConvertToUTF16(mChannel, aString, aLength,
-                                     hintCharset, nullptr,
-                                     mScriptBuf, mScriptLength);
+        nsScriptLoader::ConvertToUTF16(mChannel, aString, aLength,
+                                       hintCharset, nullptr,
+                                       mScriptBuf, mScriptLength);
 
     NS_ENSURE_SUCCESS(rv, NS_OK);
 
diff --git a/js/xpconnect/src/XPCJSContext.cpp b/js/xpconnect/src/XPCJSContext.cpp
index 93d9eeb0e908..16cad2b4e6a8 100644
--- a/js/xpconnect/src/XPCJSContext.cpp
+++ b/js/xpconnect/src/XPCJSContext.cpp
@@ -37,13 +37,13 @@
 #include "nsCCUncollectableMarker.h"
 #include "nsCycleCollectionNoteRootCallback.h"
 #include "nsCycleCollector.h"
+#include "nsScriptLoader.h"
 #include "jsapi.h"
 #include "jsprf.h"
 #include "js/MemoryMetrics.h"
 #include "mozilla/dom/GeneratedAtomList.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/Element.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/dom/WindowBinding.h"
 #include "mozilla/jsipc/CrossProcessObjectWrappers.h"
 #include "mozilla/Atomics.h"
diff --git a/js/xpconnect/src/XPCJSRuntime.cpp b/js/xpconnect/src/XPCJSRuntime.cpp
index ae58bd7d3ec6..fa9d738a924c 100644
--- a/js/xpconnect/src/XPCJSRuntime.cpp
+++ b/js/xpconnect/src/XPCJSRuntime.cpp
@@ -30,13 +30,13 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/Services.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/dom/ScriptSettings.h"
 
 #include "nsContentUtils.h"
 #include "nsCCUncollectableMarker.h"
 #include "nsCycleCollectionNoteRootCallback.h"
 #include "nsCycleCollector.h"
+#include "nsScriptLoader.h"
 #include "jsapi.h"
 #include "jsprf.h"
 #include "js/MemoryMetrics.h"
@@ -2891,8 +2891,8 @@ ReadSourceFromFilename(JSContext* cx, const char* filename, char16_t** src, size
         ptr += bytesRead;
     }
 
-    rv = ScriptLoader::ConvertToUTF16(scriptChannel, buf.get(), rawLen,
-                                      EmptyString(), nullptr, *src, *len);
+    rv = nsScriptLoader::ConvertToUTF16(scriptChannel, buf.get(), rawLen, EmptyString(),
+                                        nullptr, *src, *len);
     NS_ENSURE_SUCCESS(rv, rv);
 
     if (!*src)
diff --git a/parser/html/nsHtml5DocumentBuilder.cpp b/parser/html/nsHtml5DocumentBuilder.cpp
index d200ba312157..a076d920defb 100644
--- a/parser/html/nsHtml5DocumentBuilder.cpp
+++ b/parser/html/nsHtml5DocumentBuilder.cpp
@@ -8,9 +8,9 @@
 
 #include "nsIStyleSheetLinkingElement.h"
 #include "nsStyleLinkElement.h"
+#include "nsScriptLoader.h"
 #include "nsIHTMLDocument.h"
 #include "nsNameSpaceManager.h"
-#include "mozilla/dom/ScriptLoader.h"
 
 NS_IMPL_CYCLE_COLLECTION_INHERITED(nsHtml5DocumentBuilder, nsContentSink,
                                    mOwnedElements)
diff --git a/parser/html/nsHtml5OplessBuilder.cpp b/parser/html/nsHtml5OplessBuilder.cpp
index 65b97ffc7282..ac1c03f10682 100644
--- a/parser/html/nsHtml5OplessBuilder.cpp
+++ b/parser/html/nsHtml5OplessBuilder.cpp
@@ -6,8 +6,8 @@
 
 #include "nsHtml5OplessBuilder.h"
 
+#include "nsScriptLoader.h"
 #include "mozilla/css/Loader.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "nsIDocShell.h"
 #include "nsIHTMLDocument.h"
 
diff --git a/parser/html/nsHtml5TreeOpExecutor.cpp b/parser/html/nsHtml5TreeOpExecutor.cpp
index 9c99da24d073..2b321f591689 100644
--- a/parser/html/nsHtml5TreeOpExecutor.cpp
+++ b/parser/html/nsHtml5TreeOpExecutor.cpp
@@ -7,10 +7,10 @@
 #include "mozilla/DebugOnly.h"
 #include "mozilla/Likely.h"
 #include "mozilla/dom/nsCSPService.h"
-#include "mozilla/dom/ScriptLoader.h"
 
 #include "nsError.h"
 #include "nsHtml5TreeOpExecutor.h"
+#include "nsScriptLoader.h"
 #include "nsIContentViewer.h"
 #include "nsIContentSecurityPolicy.h"
 #include "nsIDocShellTreeItem.h"
@@ -953,8 +953,8 @@ nsHtml5TreeOpExecutor::PreloadScript(const nsAString& aURL,
     return;
   }
   mDocument->ScriptLoader()->PreloadURI(uri, aCharset, aType, aCrossOrigin,
-                                           aIntegrity, aScriptFromHead,
-                                           mSpeculationReferrerPolicy);
+                                        aIntegrity, aScriptFromHead,
+                                        mSpeculationReferrerPolicy);
 }
 
 void
diff --git a/parser/html/nsParserUtils.cpp b/parser/html/nsParserUtils.cpp
index 353340734a2e..bf4ca6546b6f 100644
--- a/parser/html/nsParserUtils.cpp
+++ b/parser/html/nsParserUtils.cpp
@@ -9,6 +9,7 @@
 #include "nsXPCOM.h"
 #include "nsISupportsPrimitives.h"
 #include "nsXPIDLString.h"
+#include "nsScriptLoader.h"
 #include "nsEscape.h"
 #include "nsIParser.h"
 #include "nsIDTD.h"
@@ -35,7 +36,6 @@
 #include "nsTreeSanitizer.h"
 #include "nsHtml5Module.h"
 #include "mozilla/dom/DocumentFragment.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "NullPrincipal.h"
 
 #define XHTML_DIV_TAG "div xmlns=\"http://www.w3.org/1999/xhtml\""
@@ -148,7 +148,7 @@ nsParserUtils::ParseFragment(const nsAString& aFragment,
   nsAutoScriptBlockerSuppressNodeRemoved autoBlocker;
 
   // stop scripts
-  RefPtr<ScriptLoader> loader;
+  RefPtr<nsScriptLoader> loader;
   bool scripts_enabled = false;
   if (document) {
     loader = document->ScriptLoader();
diff --git a/parser/htmlparser/nsParser.cpp b/parser/htmlparser/nsParser.cpp
index 8301b9898822..0ebe217694cf 100644
--- a/parser/htmlparser/nsParser.cpp
+++ b/parser/htmlparser/nsParser.cpp
@@ -28,6 +28,7 @@
 #include "nsIFragmentContentSink.h"
 #include "nsStreamUtils.h"
 #include "nsHTMLTokenizer.h"
+#include "nsScriptLoader.h"
 #include "nsDataHashtable.h"
 #include "nsXPCOMCIDInternal.h"
 #include "nsMimeTypes.h"
@@ -39,7 +40,6 @@
 #include "nsIHTMLContentSink.h"
 
 #include "mozilla/dom/EncodingUtils.h"
-#include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/BinarySearch.h"
 
 using namespace mozilla;