diff --git a/dom/base/nsIDocument.h b/dom/base/nsIDocument.h
index 90bfa855ee88..13abdf7dd68e 100644
--- a/dom/base/nsIDocument.h
+++ b/dom/base/nsIDocument.h
@@ -2867,7 +2867,7 @@ public:
     mozilla::dom::DOMIntersectionObserver* aObserver) = 0;
   virtual void RemoveIntersectionObserver(
     mozilla::dom::DOMIntersectionObserver* aObserver) = 0;
-  
+
   virtual void UpdateIntersectionObservations() = 0;
   virtual void ScheduleIntersectionObserverNotification() = 0;
   virtual void NotifyIntersectionObservers() = 0;
diff --git a/dom/xml/XMLDocument.cpp b/dom/xml/XMLDocument.cpp
index 54b880666fec..4ee339dbcdbb 100644
--- a/dom/xml/XMLDocument.cpp
+++ b/dom/xml/XMLDocument.cpp
@@ -9,7 +9,7 @@
 #include "nsParserCIID.h"
 #include "nsCharsetSource.h"
 #include "nsIXMLContentSink.h"
-#include "nsPresContext.h" 
+#include "nsPresContext.h"
 #include "nsIContent.h"
 #include "nsIContentViewerContainer.h"
 #include "nsIContentViewer.h"
@@ -61,8 +61,8 @@ using namespace mozilla::dom;
 
 nsresult
 NS_NewDOMDocument(nsIDOMDocument** aInstancePtrResult,
-                  const nsAString& aNamespaceURI, 
-                  const nsAString& aQualifiedName, 
+                  const nsAString& aNamespaceURI,
+                  const nsAString& aQualifiedName,
                   nsIDOMDocumentType* aDoctype,
                   nsIURI* aDocumentURI,
                   nsIURI* aBaseURI,
@@ -74,7 +74,7 @@ NS_NewDOMDocument(nsIDOMDocument** aInstancePtrResult,
   // Note: can't require that aDocumentURI/aBaseURI/aPrincipal be non-null,
   // since at least one caller (XMLHttpRequest) doesn't have decent args to
   // pass in.
-  
+
   nsresult rv;
 
   *aInstancePtrResult = nullptr;
@@ -152,7 +152,7 @@ NS_NewDOMDocument(nsIDOMDocument** aInstancePtrResult,
   // XMLDocuments and documents "created in memory" get to be UTF-8 by default,
   // unlike the legacy HTML mess
   doc->SetDocumentCharacterSet(NS_LITERAL_CSTRING("UTF-8"));
-  
+
   if (aDoctype) {
     nsCOMPtr<nsINode> doctypeAsNode = do_QueryInterface(aDoctype);
     ErrorResult result;
@@ -161,7 +161,7 @@ NS_NewDOMDocument(nsIDOMDocument** aInstancePtrResult,
       return result.StealNSResult();
     }
   }
-  
+
   if (!aQualifiedName.IsEmpty()) {
     ErrorResult result;
     nsCOMPtr<Element> root =
@@ -313,7 +313,7 @@ XMLDocument::Load(const nsAString& aUrl, CallerType aCallerType,
     docForWarning->WarnOnceAbout(nsIDocument::eChromeUseOfDOM3LoadMethod);
   } else {
     docForWarning->WarnOnceAbout(nsIDocument::eUseOfDOM3LoadMethod);
-  } 
+  }
 
   nsIURI *baseURI = mDocumentURI;
   nsAutoCString charset;
@@ -404,7 +404,7 @@ XMLDocument::Load(const nsAString& aUrl, CallerType aCallerType,
 
   nsCOMPtr<nsIChannel> channel;
   // nsIRequest::LOAD_BACKGROUND prevents throbber from becoming active,
-  // which in turn keeps STOP button from becoming active  
+  // which in turn keeps STOP button from becoming active
   rv = NS_NewChannel(getter_AddRefs(channel),
                      uri,
                      callingDoc ? callingDoc.get() :
@@ -438,8 +438,8 @@ XMLDocument::Load(const nsAString& aUrl, CallerType aCallerType,
 
   // Prepare for loading the XML document "into oneself"
   nsCOMPtr<nsIStreamListener> listener;
-  if (NS_FAILED(rv = StartDocumentLoad(kLoadAsData, channel, 
-                                       loadGroup, nullptr, 
+  if (NS_FAILED(rv = StartDocumentLoad(kLoadAsData, channel,
+                                       loadGroup, nullptr,
                                        getter_AddRefs(listener),
                                        false))) {
     NS_ERROR("XMLDocument::Load: Failed to start the document load.");
@@ -521,7 +521,7 @@ XMLDocument::StartDocumentLoad(const char* aCommand,
 {
   nsresult rv = nsDocument::StartDocumentLoad(aCommand,
                                               aChannel, aLoadGroup,
-                                              aContainer, 
+                                              aContainer,
                                               aDocListener, aReset, aSink);
   if (NS_FAILED(rv)) return rv;
 
@@ -545,7 +545,7 @@ XMLDocument::StartDocumentLoad(const char* aCommand,
   NS_ENSURE_SUCCESS(rv, rv);
 
   nsCOMPtr<nsIXMLContentSink> sink;
-    
+
   if (aSink) {
     sink = do_QueryInterface(aSink);
   }
@@ -566,7 +566,7 @@ XMLDocument::StartDocumentLoad(const char* aCommand,
 
   NS_ASSERTION(mChannel, "How can we not have a channel here?");
   mChannelIsPending = true;
-  
+
   SetDocumentCharacterSet(charset);
   mParser->SetDocumentCharset(charset, charsetSource);
   mParser->SetCommand(aCommand);
diff --git a/dom/xslt/xslt/txMozillaXSLTProcessor.cpp b/dom/xslt/xslt/txMozillaXSLTProcessor.cpp
index dc1e22e48900..d6100447c8d1 100644
--- a/dom/xslt/xslt/txMozillaXSLTProcessor.cpp
+++ b/dom/xslt/xslt/txMozillaXSLTProcessor.cpp
@@ -529,7 +529,7 @@ txMozillaXSLTProcessor::AddXSLTParam(const nsString& aName,
     txVariable* var = static_cast<txVariable*>(mVariables.get(varName));
     if (var) {
         var->setValue(value);
-        
+
         return NS_OK;
     }
 
@@ -589,7 +589,7 @@ NS_IMETHODIMP
 txMozillaXSLTProcessor::ImportStylesheet(nsIDOMNode *aStyle)
 {
     NS_ENSURE_TRUE(aStyle, NS_ERROR_NULL_POINTER);
-    
+
     // We don't support importing multiple stylesheets yet.
     NS_ENSURE_TRUE(!mStylesheetDocument && !mStylesheet,
                    NS_ERROR_NOT_IMPLEMENTED);
@@ -598,7 +598,7 @@ txMozillaXSLTProcessor::ImportStylesheet(nsIDOMNode *aStyle)
     if (!node || !nsContentUtils::SubjectPrincipalOrSystemIfNativeCaller()->Subsumes(node->NodePrincipal())) {
         return NS_ERROR_DOM_SECURITY_ERR;
     }
-    
+
     nsCOMPtr<nsINode> styleNode = do_QueryInterface(aStyle);
     NS_ENSURE_TRUE(styleNode &&
                    (styleNode->IsElement() ||
@@ -675,12 +675,12 @@ txMozillaXSLTProcessor::TransformToDoc(nsIDOMDocument **aResult,
     if (NS_SUCCEEDED(rv)) {
         rv = txXSLTProcessor::execute(es);
     }
-    
+
     nsresult endRv = es.end(rv);
     if (NS_SUCCEEDED(rv)) {
       rv = endRv;
     }
-    
+
     if (NS_SUCCEEDED(rv)) {
         if (aResult) {
             txAOutputXMLEventHandler* handler =
@@ -934,7 +934,7 @@ txMozillaXSLTProcessor::SetParameter(const nsAString & aNamespaceURI,
         default:
         {
             return NS_ERROR_FAILURE;
-        }        
+        }
     }
 
     int32_t nsId = kNameSpaceID_Unknown;
@@ -1152,14 +1152,14 @@ txMozillaXSLTProcessor::notifyError()
         if (rv.Failed()) {
             return;
         }
-    
+
         element->AppendChild(*sourceElement, rv);
         if (rv.Failed()) {
             return;
         }
 
         text = document->CreateTextNode(mSourceText);
-    
+
         sourceElement->AppendChild(*text, rv);
         if (rv.Failed()) {
             return;