diff --git a/Cargo.lock b/Cargo.lock
index 1b46032347de..5acdf10aef62 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1284,7 +1284,7 @@ dependencies = [
 
 [[package]]
 name = "gleam"
-version = "0.6.15"
+version = "0.6.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3315,7 +3315,7 @@ dependencies = [
  "dwrote 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "freetype 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fxhash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3366,7 +3366,7 @@ dependencies = [
  "euclid 0.19.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "foreign-types 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fxhash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "nsstring 0.1.0",
  "rayon 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3624,7 +3624,7 @@ dependencies = [
 "checksum generic-array 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3c0f28c2f5bfb5960175af447a2da7c18900693738343dc896ffbcabd9839592"
 "checksum generic-array 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ef25c5683767570c2bbd7deba372926a55eaae9982d7726ee2a1050239d45b9d"
 "checksum gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "39a23d5e872a275135d66895d954269cf5e8661d234eb1c2480f4ce0d586acbd"
-"checksum gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)" = "43edfa3a4321024d7dac1625cf154ef0c16996a6a384d066480e306ebd39fecc"
+"checksum gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)" = "39bb69499005e11b7b7cc0af38404a1bc0f53d954bffa8adcdb6e8d5b14f75d5"
 "checksum glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "8be18de09a56b60ed0edf84bc9df007e30040691af7acd1c41874faac5895bfb"
 "checksum goblin 0.0.17 (registry+https://github.com/rust-lang/crates.io-index)" = "5911d7df7b8f65ab676c5327b50acea29d3c6a1a4ad05e444cf5dce321b26db2"
 "checksum guid_win 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "87261686cc5e35b6584f4c2a430c2b153d8a92ab1ef820c16be34c1df8f5f58b"
diff --git a/dom/base/Document.cpp b/dom/base/Document.cpp
index 8aaf72e3ea7d..58c96a048d85 100644
--- a/dom/base/Document.cpp
+++ b/dom/base/Document.cpp
@@ -4301,6 +4301,13 @@ static void NotifyActivityChanged(nsISupports* aSupports, void* aUnused) {
       do_QueryInterface(aSupports));
   if (objectDocumentActivity) {
     objectDocumentActivity->NotifyOwnerDocumentActivityChanged();
+  } else {
+    nsCOMPtr<nsIImageLoadingContent> imageLoadingContent(
+        do_QueryInterface(aSupports));
+    if (imageLoadingContent) {
+      auto ilc = static_cast<nsImageLoadingContent*>(imageLoadingContent.get());
+      ilc->NotifyOwnerDocumentActivityChanged();
+    }
   }
 }
 
diff --git a/dom/base/domerr.msg b/dom/base/domerr.msg
index d011f9dfde53..078a1362efa4 100644
--- a/dom/base/domerr.msg
+++ b/dom/base/domerr.msg
@@ -163,3 +163,8 @@ DOM4_MSG_DEF(InvalidStateError, "XMLHttpRequest state must not be LOADING or DON
 DOM4_MSG_DEF(InvalidStateError, "responseXML is only available if responseType is '' or 'document'.", NS_ERROR_DOM_INVALID_STATE_XHR_HAS_WRONG_RESPONSETYPE_FOR_RESPONSEXML)
 DOM4_MSG_DEF(InvalidStateError, "responseText is only available if responseType is '' or 'text'.", NS_ERROR_DOM_INVALID_STATE_XHR_HAS_WRONG_RESPONSETYPE_FOR_RESPONSETEXT)
 DOM4_MSG_DEF(InvalidAccessError, "synchronous XMLHttpRequests do not support timeout and responseType.", NS_ERROR_DOM_INVALID_ACCESS_XHR_TIMEOUT_AND_RESPONSETYPE_UNSUPPORTED_FOR_SYNC)
+
+/* Image decode errors. */
+DOM4_MSG_DEF(EncodingError, "Node bound to inactive document.", NS_ERROR_DOM_IMAGE_INACTIVE_DOCUMENT)
+DOM4_MSG_DEF(EncodingError, "Invalid image request.", NS_ERROR_DOM_IMAGE_INVALID_REQUEST)
+DOM4_MSG_DEF(EncodingError, "Invalid encoded image data.", NS_ERROR_DOM_IMAGE_BROKEN)
diff --git a/dom/base/nsImageLoadingContent.cpp b/dom/base/nsImageLoadingContent.cpp
index d3f19748eb37..e187d793c086 100644
--- a/dom/base/nsImageLoadingContent.cpp
+++ b/dom/base/nsImageLoadingContent.cpp
@@ -95,6 +95,8 @@ nsImageLoadingContent::nsImageLoadingContent()
     : mCurrentRequestFlags(0),
       mPendingRequestFlags(0),
       mObserverList(nullptr),
+      mOutstandingDecodePromises(0),
+      mRequestGeneration(0),
       mImageBlockingStatus(nsIContentPolicy::ACCEPT),
       mLoadingEnabled(true),
       mIsImageStateForced(false),
@@ -120,17 +122,21 @@ nsImageLoadingContent::nsImageLoadingContent()
 void nsImageLoadingContent::DestroyImageLoadingContent() {
   // Cancel our requests so they won't hold stale refs to us
   // NB: Don't ask to discard the images here.
+  RejectDecodePromises(NS_ERROR_DOM_IMAGE_INVALID_REQUEST);
   ClearCurrentRequest(NS_BINDING_ABORTED);
   ClearPendingRequest(NS_BINDING_ABORTED);
 }
 
 nsImageLoadingContent::~nsImageLoadingContent() {
-  NS_ASSERTION(!mCurrentRequest && !mPendingRequest,
-               "DestroyImageLoadingContent not called");
-  NS_ASSERTION(!mObserverList.mObserver && !mObserverList.mNext,
-               "Observers still registered?");
-  NS_ASSERTION(mScriptedObservers.IsEmpty(),
-               "Scripted observers still registered?");
+  MOZ_ASSERT(!mCurrentRequest && !mPendingRequest,
+             "DestroyImageLoadingContent not called");
+  MOZ_ASSERT(!mObserverList.mObserver && !mObserverList.mNext,
+             "Observers still registered?");
+  MOZ_ASSERT(mScriptedObservers.IsEmpty(),
+             "Scripted observers still registered?");
+  MOZ_ASSERT(mOutstandingDecodePromises == 0,
+             "Decode promises still unfulfilled?");
+  MOZ_ASSERT(mDecodePromises.IsEmpty(), "Decode promises still unfulfilled?");
 }
 
 /*
@@ -204,6 +210,11 @@ nsImageLoadingContent::Notify(imgIRequest* aRequest, int32_t aType,
     return OnLoadComplete(aRequest, status);
   }
 
+  if (aType == imgINotificationObserver::FRAME_COMPLETE &&
+      mCurrentRequest == aRequest) {
+    MaybeResolveDecodePromises();
+  }
+
   if (aType == imgINotificationObserver::DECODE_COMPLETE) {
     nsCOMPtr<imgIContainer> container;
     aRequest->GetImage(getter_AddRefs(container));
@@ -260,6 +271,7 @@ nsresult nsImageLoadingContent::OnLoadComplete(imgIRequest* aRequest,
   nsCOMPtr<nsINode> thisNode =
       do_QueryInterface(static_cast<nsIImageLoadingContent*>(this));
   SVGObserverUtils::InvalidateDirectRenderingObservers(thisNode->AsElement());
+  MaybeResolveDecodePromises();
 
   return NS_OK;
 }
@@ -334,6 +346,166 @@ void nsImageLoadingContent::SetLoadingEnabled(bool aLoadingEnabled) {
   }
 }
 
+already_AddRefed<Promise> nsImageLoadingContent::QueueDecodeAsync(
+    ErrorResult& aRv) {
+  Document* doc = GetOurOwnerDoc();
+  RefPtr<Promise> promise = Promise::Create(doc->GetScopeObject(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  class QueueDecodeTask final : public Runnable {
+   public:
+    QueueDecodeTask(nsImageLoadingContent* aOwner, Promise* aPromise,
+                    uint32_t aRequestGeneration)
+        : Runnable("nsImageLoadingContent::QueueDecodeTask"),
+          mOwner(aOwner),
+          mPromise(aPromise),
+          mRequestGeneration(aRequestGeneration) {}
+
+    NS_IMETHOD Run() override {
+      mOwner->DecodeAsync(std::move(mPromise), mRequestGeneration);
+      return NS_OK;
+    }
+
+   private:
+    RefPtr<nsImageLoadingContent> mOwner;
+    RefPtr<Promise> mPromise;
+    uint32_t mRequestGeneration;
+  };
+
+  if (++mOutstandingDecodePromises == 1) {
+    MOZ_ASSERT(mDecodePromises.IsEmpty());
+    doc->RegisterActivityObserver(this);
+  }
+
+  auto task = MakeRefPtr<QueueDecodeTask>(this, promise, mRequestGeneration);
+  nsContentUtils::RunInStableState(task.forget());
+  return promise.forget();
+}
+
+void nsImageLoadingContent::DecodeAsync(RefPtr<Promise>&& aPromise,
+                                        uint32_t aRequestGeneration) {
+  MOZ_ASSERT(nsContentUtils::IsInStableOrMetaStableState());
+  MOZ_ASSERT(aPromise);
+  MOZ_ASSERT(mOutstandingDecodePromises > mDecodePromises.Length());
+
+  // The request may have gotten updated since the decode call was issued.
+  if (aRequestGeneration != mRequestGeneration) {
+    aPromise->MaybeReject(NS_ERROR_DOM_IMAGE_INVALID_REQUEST);
+    // We never got placed in mDecodePromises, so we must ensure we decrement
+    // the counter explicitly.
+    --mOutstandingDecodePromises;
+    MaybeDeregisterActivityObserver();
+    return;
+  }
+
+  bool wasEmpty = mDecodePromises.IsEmpty();
+  mDecodePromises.AppendElement(std::move(aPromise));
+  if (wasEmpty) {
+    MaybeResolveDecodePromises();
+  }
+}
+
+void nsImageLoadingContent::MaybeResolveDecodePromises() {
+  if (mDecodePromises.IsEmpty()) {
+    return;
+  }
+
+  if (!mCurrentRequest) {
+    RejectDecodePromises(NS_ERROR_DOM_IMAGE_INVALID_REQUEST);
+    return;
+  }
+
+  // Only can resolve if our document is the active document. If not we are
+  // supposed to reject the promise, even if it was fulfilled successfully.
+  if (!GetOurOwnerDoc()->IsCurrentActiveDocument()) {
+    RejectDecodePromises(NS_ERROR_DOM_IMAGE_INACTIVE_DOCUMENT);
+    return;
+  }
+
+  // If any error occurred while decoding, we need to reject first.
+  uint32_t status = imgIRequest::STATUS_NONE;
+  mCurrentRequest->GetImageStatus(&status);
+  if (status & imgIRequest::STATUS_ERROR) {
+    RejectDecodePromises(NS_ERROR_DOM_IMAGE_BROKEN);
+    return;
+  }
+
+  // We need the size to bother with requesting a decode, as we are either
+  // blocked on validation or metadata decoding.
+  if (!(status & imgIRequest::STATUS_SIZE_AVAILABLE)) {
+    return;
+  }
+
+  // Check the surface cache status and/or request decoding begin. We do this
+  // before LOAD_COMPLETE because we want to start as soon as possible.
+  uint32_t flags = imgIContainer::FLAG_HIGH_QUALITY_SCALING |
+                   imgIContainer::FLAG_AVOID_REDECODE_FOR_SIZE;
+  if (!mCurrentRequest->RequestDecodeWithResult(flags)) {
+    return;
+  }
+
+  // We can only fulfill the promises once we have all the data.
+  if (!(status & imgIRequest::STATUS_LOAD_COMPLETE)) {
+    return;
+  }
+
+  for (auto& promise : mDecodePromises) {
+    promise->MaybeResolveWithUndefined();
+  }
+
+  MOZ_ASSERT(mOutstandingDecodePromises >= mDecodePromises.Length());
+  mOutstandingDecodePromises -= mDecodePromises.Length();
+  mDecodePromises.Clear();
+  MaybeDeregisterActivityObserver();
+}
+
+void nsImageLoadingContent::RejectDecodePromises(nsresult aStatus) {
+  if (mDecodePromises.IsEmpty()) {
+    return;
+  }
+
+  for (auto& promise : mDecodePromises) {
+    promise->MaybeReject(aStatus);
+  }
+
+  MOZ_ASSERT(mOutstandingDecodePromises >= mDecodePromises.Length());
+  mOutstandingDecodePromises -= mDecodePromises.Length();
+  mDecodePromises.Clear();
+  MaybeDeregisterActivityObserver();
+}
+
+void nsImageLoadingContent::MaybeAgeRequestGeneration(nsIURI* aNewURI) {
+  MOZ_ASSERT(mCurrentRequest);
+
+  // If the current request is about to change, we need to verify if the new
+  // URI matches the existing current request's URI. If it doesn't, we need to
+  // reject any outstanding promises due to the current request mutating as per
+  // step 2.2 of the decode API requirements.
+  //
+  // https://html.spec.whatwg.org/multipage/embedded-content.html#dom-img-decode
+  if (aNewURI) {
+    nsCOMPtr<nsIURI> currentURI;
+    mCurrentRequest->GetURI(getter_AddRefs(currentURI));
+
+    bool equal = false;
+    if (NS_SUCCEEDED(aNewURI->Equals(currentURI, &equal)) && equal) {
+      return;
+    }
+  }
+
+  ++mRequestGeneration;
+  RejectDecodePromises(NS_ERROR_DOM_IMAGE_INVALID_REQUEST);
+}
+
+void nsImageLoadingContent::MaybeDeregisterActivityObserver() {
+  if (mOutstandingDecodePromises == 0) {
+    MOZ_ASSERT(mDecodePromises.IsEmpty());
+    GetOurOwnerDoc()->UnregisterActivityObserver(this);
+  }
+}
+
 void nsImageLoadingContent::SetSyncDecodingHint(bool aHint) {
   if (mSyncDecodingHint == aHint) {
     return;
@@ -786,6 +958,15 @@ nsImageLoadingContent::LoadImageWithChannel(nsIChannel* aChannel,
   // Shouldn't that be done before the start of the load?
   // XXX what about shouldProcess?
 
+  // If we have a current request without a size, we know we will replace it
+  // with the PrepareNextRequest below. If the new current request is for a
+  // different URI, then we need to reject any outstanding promises.
+  if (mCurrentRequest && !HaveSize(mCurrentRequest)) {
+    nsCOMPtr<nsIURI> uri;
+    aChannel->GetOriginalURI(getter_AddRefs(uri));
+    MaybeAgeRequestGeneration(uri);
+  }
+
   // Our state might change. Watch it.
   AutoStateChanger changer(this, true);
 
@@ -944,6 +1125,13 @@ nsresult nsImageLoadingContent::LoadImage(nsIURI* aNewURI, bool aForce,
     }
   }
 
+  // If we have a current request without a size, we know we will replace it
+  // with the PrepareNextRequest below. If the new current request is for a
+  // different URI, then we need to reject any outstanding promises.
+  if (mCurrentRequest && !HaveSize(mCurrentRequest)) {
+    MaybeAgeRequestGeneration(aNewURI);
+  }
+
   // From this point on, our image state could change. Watch it.
   AutoStateChanger changer(this, aNotify);
 
@@ -1120,11 +1308,13 @@ void nsImageLoadingContent::UpdateImageState(bool aNotify) {
   } else if (!mCurrentRequest) {
     // No current request means error, since we weren't disabled or suppressed
     mBroken = true;
+    RejectDecodePromises(NS_ERROR_DOM_IMAGE_BROKEN);
   } else {
     uint32_t currentLoadStatus;
     nsresult rv = mCurrentRequest->GetImageStatus(&currentLoadStatus);
     if (NS_FAILED(rv) || (currentLoadStatus & imgIRequest::STATUS_ERROR)) {
       mBroken = true;
+      RejectDecodePromises(NS_ERROR_DOM_IMAGE_BROKEN);
     } else if (!(currentLoadStatus & imgIRequest::STATUS_SIZE_AVAILABLE)) {
       mLoading = true;
     }
@@ -1135,6 +1325,7 @@ void nsImageLoadingContent::UpdateImageState(bool aNotify) {
 }
 
 void nsImageLoadingContent::CancelImageRequests(bool aNotify) {
+  RejectDecodePromises(NS_ERROR_DOM_IMAGE_INVALID_REQUEST);
   AutoStateChanger changer(this, aNotify);
   ClearPendingRequest(NS_BINDING_ABORTED, Some(OnNonvisible::DISCARD_IMAGES));
   ClearCurrentRequest(NS_BINDING_ABORTED, Some(OnNonvisible::DISCARD_IMAGES));
@@ -1183,6 +1374,7 @@ nsresult nsImageLoadingContent::FireEvent(const nsAString& aEventType,
                                           bool aIsCancelable) {
   if (nsContentUtils::DocumentInactiveForImageLoads(GetOurOwnerDoc())) {
     // Don't bother to fire any events, especially error events.
+    RejectDecodePromises(NS_ERROR_DOM_IMAGE_INACTIVE_DOCUMENT);
     return NS_OK;
   }
 
@@ -1315,6 +1507,13 @@ class ImageRequestAutoLock {
 void nsImageLoadingContent::MakePendingRequestCurrent() {
   MOZ_ASSERT(mPendingRequest);
 
+  // If we have a pending request, we know that there is an existing current
+  // request with size information. If the pending request is for a different
+  // URI, then we need to reject any outstanding promises.
+  nsCOMPtr<nsIURI> uri;
+  mPendingRequest->GetURI(getter_AddRefs(uri));
+  MaybeAgeRequestGeneration(uri);
+
   // Lock mCurrentRequest for the duration of this method.  We do this because
   // PrepareCurrentRequest() might unlock mCurrentRequest.  If mCurrentRequest
   // and mPendingRequest are both requests for the same image, unlocking
@@ -1408,6 +1607,12 @@ bool nsImageLoadingContent::HaveSize(imgIRequest* aImage) {
   return (NS_SUCCEEDED(rv) && (status & imgIRequest::STATUS_SIZE_AVAILABLE));
 }
 
+void nsImageLoadingContent::NotifyOwnerDocumentActivityChanged() {
+  if (!GetOurOwnerDoc()->IsCurrentActiveDocument()) {
+    RejectDecodePromises(NS_ERROR_DOM_IMAGE_INACTIVE_DOCUMENT);
+  }
+}
+
 void nsImageLoadingContent::BindToTree(Document* aDocument, nsIContent* aParent,
                                        nsIContent* aBindingParent) {
   // We may be getting connected, if so our image should be tracked,
diff --git a/dom/base/nsImageLoadingContent.h b/dom/base/nsImageLoadingContent.h
index e422dab9244b..6f02cffaf775 100644
--- a/dom/base/nsImageLoadingContent.h
+++ b/dom/base/nsImageLoadingContent.h
@@ -23,6 +23,7 @@
 #include "mozilla/ErrorResult.h"
 #include "nsIContentPolicy.h"
 #include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/Promise.h"
 #include "mozilla/net/ReferrerPolicy.h"
 #include "nsAttrValue.h"
 
@@ -82,6 +83,12 @@ class nsImageLoadingContent : public nsIImageLoadingContent {
    */
   void SetSyncDecodingHint(bool aHint);
 
+  /**
+   * Notify us that the document state has changed. Called by nsDocument so that
+   * we may reject any promises which require the document to be active.
+   */
+  void NotifyOwnerDocumentActivityChanged();
+
  protected:
   enum ImageLoadType {
     // Most normal image loads
@@ -230,6 +237,18 @@ class nsImageLoadingContent : public nsIImageLoadingContent {
   uint32_t NaturalWidth();
   uint32_t NaturalHeight();
 
+  /**
+   * Create a promise and queue a microtask which will ensure the current
+   * request (after any pending loads are applied) has requested a full decode.
+   * The promise is fulfilled once the request has a fully decoded surface that
+   * is available for drawing, or an error condition occurrs (e.g. broken image,
+   * current request is updated, etc).
+   *
+   * https://html.spec.whatwg.org/multipage/embedded-content.html#dom-img-decode
+   */
+  already_AddRefed<mozilla::dom::Promise> QueueDecodeAsync(
+      mozilla::ErrorResult& aRv);
+
   enum class ImageDecodingType : uint8_t {
     Auto,
     Async,
@@ -240,6 +259,38 @@ class nsImageLoadingContent : public nsIImageLoadingContent {
   static const nsAttrValue::EnumTable* kDecodingTableDefault;
 
  private:
+  /**
+   * Enqueue and/or fulfill a promise created by QueueDecodeAsync.
+   */
+  void DecodeAsync(RefPtr<mozilla::dom::Promise>&& aPromise,
+                   uint32_t aRequestGeneration);
+
+  /**
+   * Attempt to resolve all queued promises based on the state of the current
+   * request. If the current request does not yet have all of the encoded data,
+   * or the decoding has not yet completed, it will return without changing the
+   * promise states.
+   */
+  void MaybeResolveDecodePromises();
+
+  /**
+   * Reject all queued promises with the given status.
+   */
+  void RejectDecodePromises(nsresult aStatus);
+
+  /**
+   * Age the generation counter if we have a new current request with a
+   * different URI. If the generation counter is aged, then all queued promises
+   * will also be rejected.
+   */
+  void MaybeAgeRequestGeneration(nsIURI* aNewURI);
+
+  /**
+   * Deregister as an observer for the owner document's activity notifications
+   * if we have no outstanding decode promises.
+   */
+  void MaybeDeregisterActivityObserver();
+
   /**
    * Struct used to manage the native image observers.
    */
@@ -483,6 +534,12 @@ class nsImageLoadingContent : public nsIImageLoadingContent {
    */
   nsTArray<RefPtr<ScriptedImageObserver>> mScriptedObservers;
 
+  /**
+   * Promises created by QueueDecodeAsync that are still waiting to be
+   * fulfilled by the image being fully decoded.
+   */
+  nsTArray<RefPtr<mozilla::dom::Promise>> mDecodePromises;
+
   /**
    * When mIsImageStateForced is true, this holds the ImageState that we'll
    * return in ImageState().
@@ -491,6 +548,23 @@ class nsImageLoadingContent : public nsIImageLoadingContent {
 
   mozilla::TimeStamp mMostRecentRequestChange;
 
+  /**
+   * Total number of outstanding decode promises, including those stored in
+   * mDecodePromises and those embedded in runnables waiting to be enqueued.
+   * This is used to determine whether we need to register as an observer for
+   * document activity notifications.
+   */
+  size_t mOutstandingDecodePromises;
+
+  /**
+   * An incrementing counter representing the current request generation;
+   * Each time mCurrentRequest is modified with a different URI, this will
+   * be incremented. Each QueueDecodeAsync call will cache the generation
+   * of the current request so that when it is processed, it knows if it
+   * should have rejected because the request changed.
+   */
+  uint32_t mRequestGeneration;
+
   int16_t mImageBlockingStatus;
   bool mLoadingEnabled : 1;
 
diff --git a/dom/base/nsNodeUtils.cpp b/dom/base/nsNodeUtils.cpp
index 2e2ede74dca2..811a607a0152 100644
--- a/dom/base/nsNodeUtils.cpp
+++ b/dom/base/nsNodeUtils.cpp
@@ -499,6 +499,16 @@ already_AddRefed<nsINode> nsNodeUtils::CloneAndAdopt(
         nsObjectLoadingContent* olc =
             static_cast<nsObjectLoadingContent*>(objectLoadingContent.get());
         olc->NotifyOwnerDocumentActivityChanged();
+      } else {
+        // HTMLImageElement::FromNode is insufficient since we need this for
+        // <svg:image> as well.
+        nsCOMPtr<nsIImageLoadingContent> imageLoadingContent(
+            do_QueryInterface(aNode));
+        if (imageLoadingContent) {
+          auto ilc =
+              static_cast<nsImageLoadingContent*>(imageLoadingContent.get());
+          ilc->NotifyOwnerDocumentActivityChanged();
+        }
       }
     }
 
diff --git a/dom/base/nsObjectLoadingContent.cpp b/dom/base/nsObjectLoadingContent.cpp
index f15d358c36a2..38b2fc5ac946 100644
--- a/dom/base/nsObjectLoadingContent.cpp
+++ b/dom/base/nsObjectLoadingContent.cpp
@@ -927,6 +927,7 @@ void nsObjectLoadingContent::NotifyOwnerDocumentActivityChanged() {
   if (mInstanceOwner || mInstantiating) {
     QueueCheckPluginStopEvent();
   }
+  nsImageLoadingContent::NotifyOwnerDocumentActivityChanged();
 }
 
 // nsIRequestObserver
diff --git a/dom/html/HTMLImageElement.cpp b/dom/html/HTMLImageElement.cpp
index b4c8d758da78..8dc7ee96aeec 100644
--- a/dom/html/HTMLImageElement.cpp
+++ b/dom/html/HTMLImageElement.cpp
@@ -191,6 +191,10 @@ void HTMLImageElement::GetDecoding(nsAString& aValue) {
   GetEnumAttr(nsGkAtoms::decoding, kDecodingTableDefault->tag, aValue);
 }
 
+already_AddRefed<Promise> HTMLImageElement::Decode(ErrorResult& aRv) {
+  return nsImageLoadingContent::QueueDecodeAsync(aRv);
+}
+
 bool HTMLImageElement::ParseAttribute(int32_t aNamespaceID, nsAtom* aAttribute,
                                       const nsAString& aValue,
                                       nsIPrincipal* aMaybeScriptedPrincipal,
diff --git a/dom/html/HTMLImageElement.h b/dom/html/HTMLImageElement.h
index d6acf914218b..dc96a64163d1 100644
--- a/dom/html/HTMLImageElement.h
+++ b/dom/html/HTMLImageElement.h
@@ -180,6 +180,8 @@ class HTMLImageElement final : public nsGenericHTMLElement,
   }
   void GetDecoding(nsAString& aValue);
 
+  already_AddRefed<Promise> Decode(ErrorResult& aRv);
+
   net::ReferrerPolicy GetImageReferrerPolicy() override {
     return GetReferrerPolicyAsEnum();
   }
diff --git a/dom/localstorage/ActorsParent.cpp b/dom/localstorage/ActorsParent.cpp
index c1afc10c32f9..f5e1a8411ce2 100644
--- a/dom/localstorage/ActorsParent.cpp
+++ b/dom/localstorage/ActorsParent.cpp
@@ -2170,8 +2170,12 @@ class LSRequestBase : public DatastoreOperationBase,
  private:
   void SendReadyMessage();
 
+  nsresult SendReadyMessageInternal();
+
   void Finish();
 
+  void FinishInternal();
+
   void SendResults();
 
  protected:
@@ -5703,27 +5707,49 @@ void LSRequestBase::SendReadyMessage() {
     MaybeSetFailureCode(NS_ERROR_FAILURE);
   }
 
-  if (MayProceed()) {
-    Unused << SendReady();
+  nsresult rv = SendReadyMessageInternal();
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    MaybeSetFailureCode(rv);
 
-    mState = State::WaitingForFinish;
-
-    mWaitingForFinish = true;
-  } else {
-    Cleanup();
-
-    mState = State::Completed;
+    FinishInternal();
   }
 }
 
+nsresult LSRequestBase::SendReadyMessageInternal() {
+  AssertIsOnOwningThread();
+  MOZ_ASSERT(mState == State::SendingReadyMessage);
+
+  if (!MayProceed()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (NS_WARN_IF(!SendReady())) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mState = State::WaitingForFinish;
+
+  mWaitingForFinish = true;
+
+  return NS_OK;
+}
+
 void LSRequestBase::Finish() {
   AssertIsOnOwningThread();
   MOZ_ASSERT(mState == State::WaitingForFinish);
 
-  mState = State::SendingResults;
-
   mWaitingForFinish = false;
 
+  FinishInternal();
+}
+
+void LSRequestBase::FinishInternal() {
+  AssertIsOnOwningThread();
+  MOZ_ASSERT(mState == State::SendingReadyMessage ||
+             mState == State::WaitingForFinish);
+
+  mState = State::SendingResults;
+
   // This LSRequestBase can only be held alive by the IPDL. Run() can end up
   // with clearing that last reference. So we need to add a self reference here.
   RefPtr<LSRequestBase> kungFuDeathGrip = this;
diff --git a/dom/svg/SVGImageElement.cpp b/dom/svg/SVGImageElement.cpp
index 82b978e683cf..8d64e5c54892 100644
--- a/dom/svg/SVGImageElement.cpp
+++ b/dom/svg/SVGImageElement.cpp
@@ -101,6 +101,10 @@ void SVGImageElement::GetDecoding(nsAString& aValue) {
   GetEnumAttr(nsGkAtoms::decoding, kDecodingTableDefault->tag, aValue);
 }
 
+already_AddRefed<Promise> SVGImageElement::Decode(ErrorResult& aRv) {
+  return nsImageLoadingContent::QueueDecodeAsync(aRv);
+}
+
 //----------------------------------------------------------------------
 
 nsresult SVGImageElement::LoadSVGImage(bool aForce, bool aNotify) {
diff --git a/dom/svg/SVGImageElement.h b/dom/svg/SVGImageElement.h
index 0702eaffff21..989efcd2118b 100644
--- a/dom/svg/SVGImageElement.h
+++ b/dom/svg/SVGImageElement.h
@@ -93,6 +93,8 @@ class SVGImageElement : public SVGImageElementBase,
   }
   void GetDecoding(nsAString& aValue);
 
+  already_AddRefed<Promise> Decode(ErrorResult& aRv);
+
  protected:
   nsresult LoadSVGImage(bool aForce, bool aNotify);
 
diff --git a/dom/webidl/HTMLImageElement.webidl b/dom/webidl/HTMLImageElement.webidl
index 4899f32f3e11..4b73f77eb24b 100644
--- a/dom/webidl/HTMLImageElement.webidl
+++ b/dom/webidl/HTMLImageElement.webidl
@@ -42,6 +42,8 @@ interface HTMLImageElement : HTMLElement {
   readonly attribute unsigned long naturalWidth;
   readonly attribute unsigned long naturalHeight;
   readonly attribute boolean complete;
+           [NewObject]
+           Promise<void> decode();
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
diff --git a/dom/webidl/SVGImageElement.webidl b/dom/webidl/SVGImageElement.webidl
index 4ba236bed470..eeaf66f1a90f 100644
--- a/dom/webidl/SVGImageElement.webidl
+++ b/dom/webidl/SVGImageElement.webidl
@@ -23,6 +23,8 @@ interface SVGImageElement : SVGGraphicsElement {
   readonly attribute SVGAnimatedPreserveAspectRatio preserveAspectRatio;
   [CEReactions, SetterThrows]
   attribute DOMString decoding;
+  [NewObject]
+  Promise<void> decode();
 };
 
 SVGImageElement implements MozImageLoadingContent;
diff --git a/gfx/wr/Cargo.lock b/gfx/wr/Cargo.lock
index b271b8f9c1cb..e18c6ddd7d67 100644
--- a/gfx/wr/Cargo.lock
+++ b/gfx/wr/Cargo.lock
@@ -143,7 +143,7 @@ name = "cgl"
 version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -370,7 +370,7 @@ name = "direct-composition"
 version = "0.1.0"
 dependencies = [
  "euclid 0.19.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "mozangle 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "webrender 0.60.0",
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -569,7 +569,7 @@ dependencies = [
 
 [[package]]
 name = "gleam"
-version = "0.6.15"
+version = "0.6.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1640,7 +1640,7 @@ dependencies = [
  "dwrote 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "freetype 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fxhash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.21.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1676,7 +1676,7 @@ dependencies = [
  "app_units 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "glutin 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "webrender 0.60.0",
@@ -1793,7 +1793,7 @@ dependencies = [
  "env_logger 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "font-loader 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "glutin 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.21.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1940,7 +1940,7 @@ dependencies = [
 "checksum gif 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ff3414b424657317e708489d2857d9575f4403698428b040b609b9d1c1a84a2c"
 "checksum gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "39a23d5e872a275135d66895d954269cf5e8661d234eb1c2480f4ce0d586acbd"
 "checksum gl_generator 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a795170cbd85b5a7baa58d6d7525cae6a03e486859860c220f7ebbbdd379d0a"
-"checksum gleam 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)" = "43edfa3a4321024d7dac1625cf154ef0c16996a6a384d066480e306ebd39fecc"
+"checksum gleam 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)" = "39bb69499005e11b7b7cc0af38404a1bc0f53d954bffa8adcdb6e8d5b14f75d5"
 "checksum glutin 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a70c5fe78efbd5a3b243a804ea1032053c584510f8822819f94cfb29b2100317"
 "checksum half 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d5c5f71a723d10dfc58927cbed37c3071a50afc7f073d86fd7d3e5727db890f"
 "checksum httparse 1.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "c2f407128745b78abc95c0ffbe4e5d37427fdc0d45470710cfef8c44522a2e37"
diff --git a/gfx/wr/webrender/Cargo.toml b/gfx/wr/webrender/Cargo.toml
index c9a647f182d3..fa72e784f48a 100644
--- a/gfx/wr/webrender/Cargo.toml
+++ b/gfx/wr/webrender/Cargo.toml
@@ -29,7 +29,7 @@ byteorder = "1.0"
 cfg-if = "0.1.2"
 cstr = "0.1.2"
 fxhash = "0.2.1"
-gleam = "0.6.14"
+gleam = "0.6.16"
 image = { optional = true, version = "0.21" }
 lazy_static = "1"
 log = "0.4"
diff --git a/gfx/wr/webrender/src/device/query_gl.rs b/gfx/wr/webrender/src/device/query_gl.rs
index 1ed30c8b6189..f770bb92bce0 100644
--- a/gfx/wr/webrender/src/device/query_gl.rs
+++ b/gfx/wr/webrender/src/device/query_gl.rs
@@ -8,6 +8,12 @@ use std::rc::Rc;
 
 use device::GpuFrameId;
 
+#[derive(Copy, Clone, Debug)]
+pub enum GpuDebugMethod {
+    None,
+    MarkerEXT,
+    KHR,
+}
 
 pub trait NamedTag {
     fn get_label(&self) -> &str;
@@ -69,18 +75,18 @@ pub struct GpuFrameProfile<T> {
     samplers: QuerySet<GpuSampler<T>>,
     frame_id: GpuFrameId,
     inside_frame: bool,
-    ext_debug_marker: bool
+    debug_method: GpuDebugMethod,
 }
 
 impl<T> GpuFrameProfile<T> {
-    fn new(gl: Rc<gl::Gl>, ext_debug_marker: bool) -> Self {
+    fn new(gl: Rc<gl::Gl>, debug_method: GpuDebugMethod) -> Self {
         GpuFrameProfile {
             gl,
             timers: QuerySet::new(),
             samplers: QuerySet::new(),
             frame_id: GpuFrameId::new(0),
             inside_frame: false,
-            ext_debug_marker
+            debug_method
         }
     }
 
@@ -140,7 +146,7 @@ impl<T: NamedTag> GpuFrameProfile<T> {
     fn start_timer(&mut self, tag: T) -> GpuTimeQuery {
         self.finish_timer();
 
-        let marker = GpuMarker::new(&self.gl, tag.get_label(), self.ext_debug_marker);
+        let marker = GpuMarker::new(&self.gl, tag.get_label(), self.debug_method);
 
         if let Some(query) = self.timers.add(GpuTimer { tag, time_ns: 0 }) {
             self.gl.begin_query(gl::TIME_ELAPSED, query);
@@ -186,21 +192,21 @@ pub struct GpuProfiler<T> {
     gl: Rc<gl::Gl>,
     frames: Vec<GpuFrameProfile<T>>,
     next_frame: usize,
-    ext_debug_marker: bool
+    debug_method: GpuDebugMethod
 }
 
 impl<T> GpuProfiler<T> {
-    pub fn new(gl: Rc<gl::Gl>, ext_debug_marker: bool) -> Self {
+    pub fn new(gl: Rc<gl::Gl>, debug_method: GpuDebugMethod) -> Self {
         const MAX_PROFILE_FRAMES: usize = 4;
         let frames = (0 .. MAX_PROFILE_FRAMES)
-            .map(|_| GpuFrameProfile::new(Rc::clone(&gl), ext_debug_marker))
+            .map(|_| GpuFrameProfile::new(Rc::clone(&gl), debug_method))
             .collect();
 
         GpuProfiler {
             gl,
             next_frame: 0,
             frames,
-            ext_debug_marker
+            debug_method
         }
     }
 
@@ -263,41 +269,52 @@ impl<T: NamedTag> GpuProfiler<T> {
     }
 
     pub fn start_marker(&mut self, label: &str) -> GpuMarker {
-        GpuMarker::new(&self.gl, label, self.ext_debug_marker)
+        GpuMarker::new(&self.gl, label, self.debug_method)
     }
 
     pub fn place_marker(&mut self, label: &str) {
-        GpuMarker::fire(&self.gl, label, self.ext_debug_marker)
+        GpuMarker::fire(&self.gl, label, self.debug_method)
     }
 }
 
 #[must_use]
 pub struct GpuMarker {
-    gl: Option<Rc<gl::Gl>>
+    gl: Option<(Rc<gl::Gl>, GpuDebugMethod)>,
 }
 
 impl GpuMarker {
-    fn new(gl: &Rc<gl::Gl>, message: &str, ext_debug_marker: bool) -> Self {
-        let gl = if ext_debug_marker {
-            gl.push_group_marker_ext(message);
-            Some(Rc::clone(gl))
-        } else {
-            None
+    fn new(gl: &Rc<gl::Gl>, message: &str, debug_method: GpuDebugMethod) -> Self {
+        let gl = match debug_method {
+            GpuDebugMethod::KHR => {
+              gl.push_debug_group_khr(gl::DEBUG_SOURCE_APPLICATION, 0, message);
+              Some((Rc::clone(gl), debug_method))
+            },
+            GpuDebugMethod::MarkerEXT => {
+              gl.push_group_marker_ext(message);
+              Some((Rc::clone(gl), debug_method))
+            },
+            GpuDebugMethod::None => None,
         };
         GpuMarker { gl }
     }
 
-    fn fire(gl: &Rc<gl::Gl>, message: &str, ext_debug_marker: bool) {
-        if ext_debug_marker {
-            gl.insert_event_marker_ext(message);
-        }
+    fn fire(gl: &Rc<gl::Gl>, message: &str, debug_method: GpuDebugMethod) {
+        match debug_method {
+            GpuDebugMethod::KHR => gl.debug_message_insert_khr(gl::DEBUG_SOURCE_APPLICATION, gl::DEBUG_TYPE_MARKER, 0, gl::DEBUG_SEVERITY_NOTIFICATION, message),
+            GpuDebugMethod::MarkerEXT => gl.insert_event_marker_ext(message),
+            GpuDebugMethod::None => {}
+        };
     }
 }
 
 impl Drop for GpuMarker {
     fn drop(&mut self) {
-        if let Some(ref gl) = self.gl {
-            gl.pop_group_marker_ext();
+        if let Some((ref gl, debug_method)) = self.gl {
+            match debug_method {
+                GpuDebugMethod::KHR => gl.pop_debug_group_khr(),
+                GpuDebugMethod::MarkerEXT => gl.pop_group_marker_ext(),
+                GpuDebugMethod::None => {}
+            };
         }
     }
 }
diff --git a/gfx/wr/webrender/src/renderer.rs b/gfx/wr/webrender/src/renderer.rs
index fb594fb51b92..c5b3cad1b1cb 100644
--- a/gfx/wr/webrender/src/renderer.rs
+++ b/gfx/wr/webrender/src/renderer.rs
@@ -75,7 +75,7 @@ use prim_store::DeferredResolve;
 use profiler::{BackendProfileCounters, FrameProfileCounters, TimeProfileCounter,
                GpuProfileTag, RendererProfileCounters, RendererProfileTimers};
 use profiler::{Profiler, ChangeIndicator};
-use device::query::GpuProfiler;
+use device::query::{GpuProfiler, GpuDebugMethod};
 use rayon::{ThreadPool, ThreadPoolBuilder};
 use record::ApiRecordingReceiver;
 use render_backend::{FrameId, RenderBackend};
@@ -2339,8 +2339,17 @@ impl Renderer {
             }
         })?;
 
-        let ext_debug_marker = device.supports_extension("GL_EXT_debug_marker");
-        let gpu_profile = GpuProfiler::new(Rc::clone(device.rc_gl()), ext_debug_marker);
+        let debug_support = if device.supports_extension("GL_KHR_debug") {
+            GpuDebugMethod::KHR
+        } else if device.supports_extension("GL_EXT_debug_marker") {
+            GpuDebugMethod::MarkerEXT
+        } else {
+            GpuDebugMethod::None
+        };
+
+        info!("using {:?}", debug_support);
+
+        let gpu_profile = GpuProfiler::new(Rc::clone(device.rc_gl()), debug_support);
         #[cfg(feature = "capture")]
         let read_fbo = device.create_fbo();
 
diff --git a/image/DynamicImage.cpp b/image/DynamicImage.cpp
index 4de8e96f2446..3881846ec513 100644
--- a/image/DynamicImage.cpp
+++ b/image/DynamicImage.cpp
@@ -225,6 +225,8 @@ DynamicImage::StartDecoding(uint32_t aFlags) { return NS_OK; }
 
 bool DynamicImage::StartDecodingWithResult(uint32_t aFlags) { return true; }
 
+bool DynamicImage::RequestDecodeWithResult(uint32_t aFlags) { return true; }
+
 NS_IMETHODIMP
 DynamicImage::RequestDecodeForSize(const nsIntSize& aSize, uint32_t aFlags) {
   return NS_OK;
diff --git a/image/ImageWrapper.cpp b/image/ImageWrapper.cpp
index ee9d26ba398d..04a21db02840 100644
--- a/image/ImageWrapper.cpp
+++ b/image/ImageWrapper.cpp
@@ -202,6 +202,10 @@ bool ImageWrapper::StartDecodingWithResult(uint32_t aFlags) {
   return mInnerImage->StartDecodingWithResult(aFlags);
 }
 
+bool ImageWrapper::RequestDecodeWithResult(uint32_t aFlags) {
+  return mInnerImage->RequestDecodeWithResult(aFlags);
+}
+
 NS_IMETHODIMP
 ImageWrapper::RequestDecodeForSize(const nsIntSize& aSize, uint32_t aFlags) {
   return mInnerImage->RequestDecodeForSize(aSize, aFlags);
diff --git a/image/RasterImage.cpp b/image/RasterImage.cpp
index 8466f4622783..ab293ed99e2e 100644
--- a/image/RasterImage.cpp
+++ b/image/RasterImage.cpp
@@ -339,9 +339,12 @@ LookupResult RasterImage::LookupFrame(const IntSize& aSize, uint32_t aFlags,
     return LookupResult(MatchType::NOT_FOUND);
   }
 
+  const bool syncDecode = aFlags & FLAG_SYNC_DECODE;
+  const bool avoidRedecode = aFlags & FLAG_AVOID_REDECODE_FOR_SIZE;
   if (result.Type() == MatchType::NOT_FOUND ||
-      result.Type() == MatchType::SUBSTITUTE_BECAUSE_NOT_FOUND ||
-      ((aFlags & FLAG_SYNC_DECODE) && !result)) {
+      (result.Type() == MatchType::SUBSTITUTE_BECAUSE_NOT_FOUND &&
+       !avoidRedecode) ||
+      (syncDecode && !avoidRedecode && !result)) {
     // We don't have a copy of this frame, and there's no decoder working on
     // one. (Or we're sync decoding and the existing decoder hasn't even started
     // yet.) Trigger decoding so it'll be available next time.
@@ -353,15 +356,14 @@ LookupResult RasterImage::LookupFrame(const IntSize& aSize, uint32_t aFlags,
     // The surface cache may suggest the preferred size we are supposed to
     // decode at. This should only happen if we accept substitutions.
     if (!result.SuggestedSize().IsEmpty()) {
-      MOZ_ASSERT(!(aFlags & FLAG_SYNC_DECODE) &&
-                 (aFlags & FLAG_HIGH_QUALITY_SCALING));
+      MOZ_ASSERT(!syncDecode && (aFlags & FLAG_HIGH_QUALITY_SCALING));
       requestedSize = result.SuggestedSize();
     }
 
     bool ranSync = Decode(requestedSize, aFlags, aPlaybackType);
 
     // If we can or did sync decode, we should already have the frame.
-    if (ranSync || (aFlags & FLAG_SYNC_DECODE)) {
+    if (ranSync || syncDecode) {
       result =
           LookupFrameInternal(requestedSize, aFlags, aPlaybackType, aMarkUsed);
     }
@@ -375,7 +377,7 @@ LookupResult RasterImage::LookupFrame(const IntSize& aSize, uint32_t aFlags,
   // Sync decoding guarantees that we got the frame, but if it's owned by an
   // async decoder that's currently running, the contents of the frame may not
   // be available yet. Make sure we get everything.
-  if (mAllSourceData && (aFlags & FLAG_SYNC_DECODE)) {
+  if (mAllSourceData && syncDecode) {
     result.Surface()->WaitUntilFinished();
   }
 
@@ -1078,6 +1080,18 @@ bool RasterImage::StartDecodingWithResult(uint32_t aFlags) {
   return surface && surface->IsFinished();
 }
 
+bool RasterImage::RequestDecodeWithResult(uint32_t aFlags) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (mError) {
+    return false;
+  }
+
+  uint32_t flags = aFlags | FLAG_ASYNC_NOTIFY;
+  DrawableSurface surface = RequestDecodeForSizeInternal(mSize, flags);
+  return surface && surface->IsFinished();
+}
+
 NS_IMETHODIMP
 RasterImage::RequestDecodeForSize(const IntSize& aSize, uint32_t aFlags) {
   MOZ_ASSERT(NS_IsMainThread());
diff --git a/image/VectorImage.cpp b/image/VectorImage.cpp
index 6f5506194963..e0689485f239 100644
--- a/image/VectorImage.cpp
+++ b/image/VectorImage.cpp
@@ -1236,6 +1236,11 @@ bool VectorImage::StartDecodingWithResult(uint32_t aFlags) {
   return mIsFullyLoaded;
 }
 
+bool VectorImage::RequestDecodeWithResult(uint32_t aFlags) {
+  // SVG images are ready to draw when they are loaded
+  return mIsFullyLoaded;
+}
+
 NS_IMETHODIMP
 VectorImage::RequestDecodeForSize(const nsIntSize& aSize, uint32_t aFlags) {
   // Nothing to do for SVG images, though in theory we could rasterize to the
diff --git a/image/imgIContainer.idl b/image/imgIContainer.idl
index 7ab8ae63a419..e7e75adf2a3e 100644
--- a/image/imgIContainer.idl
+++ b/image/imgIContainer.idl
@@ -209,6 +209,10 @@ interface imgIContainer : nsISupports
    * (a "window into SVG space") based on the border image area, and we need to
    * be sure we don't subsequently scale that viewport in a way that distorts
    * its contents by stretching them more in one dimension than the other.
+   *
+   * FLAG_AVOID_REDECODE_FOR_SIZE: If there is already a raster surface
+   * available for this image, but it is not the same size as requested, skip
+   * starting a new decode for said size.
    */
   const unsigned long FLAG_NONE                            = 0x0;
   const unsigned long FLAG_SYNC_DECODE                     = 0x1;
@@ -222,6 +226,7 @@ interface imgIContainer : nsISupports
   const unsigned long FLAG_BYPASS_SURFACE_CACHE            = 0x100;
   const unsigned long FLAG_FORCE_PRESERVEASPECTRATIO_NONE  = 0x200;
   const unsigned long FLAG_FORCE_UNIFORM_SCALING           = 0x400;
+  const unsigned long FLAG_AVOID_REDECODE_FOR_SIZE         = 0x800;
 
   /**
    * A constant specifying the default set of decode flags (i.e., the default
@@ -472,6 +477,17 @@ interface imgIContainer : nsISupports
    */
   [noscript, notxpcom] boolean startDecodingWithResult(in uint32_t aFlags);
 
+  /*
+   * This method triggers decoding for an image, but unlike startDecoding() it
+   * enables the caller to provide more detailed information about the decode
+   * request.
+   *
+   * @param aFlags Flags of the FLAG_* variety.
+   * @return True there is a surface that satisfies the request and it is
+   *         fully decoded, else false.
+   */
+  [noscript, notxpcom] boolean requestDecodeWithResult(in uint32_t aFlags);
+
   /*
    * This method triggers decoding for an image, but unlike startDecoding() it
    * enables the caller to provide more detailed information about the decode
diff --git a/image/imgIRequest.idl b/image/imgIRequest.idl
index cebe9ad749cb..9f683ea47dcd 100644
--- a/image/imgIRequest.idl
+++ b/image/imgIRequest.idl
@@ -163,9 +163,23 @@ interface imgIRequest : nsIRequest
   /**
    * Exactly like startDecoding above except returns whether the current frame
    * of the image is complete or not.
+   *
+   * @param aFlags Flags of the FLAG_* variety. Only FLAG_ASYNC_NOTIFY
+   *               is accepted; all others are ignored.
    */
   [noscript, notxpcom] boolean startDecodingWithResult(in uint32_t aFlags);
 
+  /**
+   * This method triggers decoding for an image, but unlike startDecoding() it
+   * enables the caller to provide more detailed information about the decode
+   * request.
+   *
+   * @param aFlags Flags of the FLAG_* variety.
+   * @return True there is a surface that satisfies the request and it is
+   *         fully decoded, else false.
+   */
+  [noscript, notxpcom] boolean requestDecodeWithResult(in uint32_t aFlags);
+
   /**
    * Locks an image. If the image does not exist yet, locks it once it becomes
    * available. The lock persists for the lifetime of the imgIRequest (until
diff --git a/image/imgRequestProxy.cpp b/image/imgRequestProxy.cpp
index fc35b3cd47c6..3f1a1ebb5d0f 100644
--- a/image/imgRequestProxy.cpp
+++ b/image/imgRequestProxy.cpp
@@ -543,6 +543,24 @@ bool imgRequestProxy::StartDecodingWithResult(uint32_t aFlags) {
   return false;
 }
 
+bool imgRequestProxy::RequestDecodeWithResult(uint32_t aFlags) {
+  if (IsValidating()) {
+    mDecodeRequested = true;
+    return false;
+  }
+
+  RefPtr<Image> image = GetImage();
+  if (image) {
+    return image->RequestDecodeWithResult(aFlags);
+  }
+
+  if (GetOwner()) {
+    GetOwner()->StartDecoding();
+  }
+
+  return false;
+}
+
 NS_IMETHODIMP
 imgRequestProxy::LockImage() {
   mLockCount++;
diff --git a/netwerk/dns/nsEffectiveTLDService.cpp b/netwerk/dns/nsEffectiveTLDService.cpp
index 27a2d4a90960..463179037d55 100644
--- a/netwerk/dns/nsEffectiveTLDService.cpp
+++ b/netwerk/dns/nsEffectiveTLDService.cpp
@@ -42,11 +42,14 @@ nsEffectiveTLDService::nsEffectiveTLDService()
     : mIDNService(), mGraph(etld_dafsa::kDafsa) {}
 
 nsresult nsEffectiveTLDService::Init() {
+  if (gService) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
   nsresult rv;
   mIDNService = do_GetService(NS_IDNSERVICE_CONTRACTID, &rv);
   if (NS_FAILED(rv)) return rv;
 
-  MOZ_ASSERT(!gService);
   gService = this;
   RegisterWeakMemoryReporter(this);
 
@@ -55,7 +58,10 @@ nsresult nsEffectiveTLDService::Init() {
 
 nsEffectiveTLDService::~nsEffectiveTLDService() {
   UnregisterWeakMemoryReporter(this);
-  gService = nullptr;
+  if (mIDNService) {
+    // Only clear gService if Init() finished successfully.
+    gService = nullptr;
+  }
 }
 
 // static
diff --git a/netwerk/test/browser/browser.ini b/netwerk/test/browser/browser.ini
index 6eb2acdebd52..ea7c51ef4f8c 100644
--- a/netwerk/test/browser/browser.ini
+++ b/netwerk/test/browser/browser.ini
@@ -5,6 +5,7 @@ support-files =
   redirect.sjs
 
 [browser_about_cache.js]
+[browser_bug1535877.js]
 [browser_NetUtil.js]
 [browser_child_resource.js]
 skip-if = !crashreporter || (e10s && debug && os == "linux" && bits == 64) || debug # Bug 1370783
diff --git a/netwerk/test/browser/browser_bug1535877.js b/netwerk/test/browser/browser_bug1535877.js
new file mode 100644
index 000000000000..5af97e2886c1
--- /dev/null
+++ b/netwerk/test/browser/browser_bug1535877.js
@@ -0,0 +1,11 @@
+"use strict";
+
+add_task(_ => {
+  try {
+    Cc["@mozilla.org/network/effective-tld-service;1"]
+      .createInstance(Ci.nsISupports);
+  } catch (e) {
+    is(e.result, Cr.NS_ERROR_XPC_CI_RETURNED_FAILURE,
+       "Component creation as an instance fails with expected code");
+  }
+});
diff --git a/python/mozboot/mozboot/base.py b/python/mozboot/mozboot/base.py
index 1f5316d62f8d..630b0472ef62 100644
--- a/python/mozboot/mozboot/base.py
+++ b/python/mozboot/mozboot/base.py
@@ -673,7 +673,7 @@ class BaseBootstrapper(object):
             print('Your version of Rust (%s) is new enough.' % version)
             rustup = self.which('rustup', cargo_bin)
             if rustup:
-                self.ensure_rust_targets(rustup, version)
+                self.ensure_rust_targets(rustup)
             return
 
         if version:
@@ -697,7 +697,7 @@ class BaseBootstrapper(object):
             print('Will try to install Rust.')
             self.install_rust()
 
-    def ensure_rust_targets(self, rustup, rust_version):
+    def ensure_rust_targets(self, rustup):
         """Make sure appropriate cross target libraries are installed."""
         target_list = subprocess.check_output([rustup, 'target', 'list'])
         targets = [line.split()[0] for line in target_list.splitlines()
@@ -712,11 +712,7 @@ class BaseBootstrapper(object):
 
         if 'mobile_android' in self.application:
             # Let's add the most common targets.
-            if LooseVersion(rust_version) < '1.33':
-                arm_target = 'armv7-linux-androideabi'
-            else:
-                arm_target = 'thumbv7neon-linux-androideabi'
-            android_targets = (arm_target,
+            android_targets = ('thumbv7neon-linux-androideabi',
                                'aarch64-linux-android',
                                'i686-linux-android',
                                'x86_64-linux-android', )
diff --git a/testing/web-platform/meta/fetch/cross-origin-resource-policy/fetch.any.js.ini b/testing/web-platform/meta/fetch/cross-origin-resource-policy/fetch.any.js.ini
index c6ad5b558690..c55217a2cc8d 100644
--- a/testing/web-platform/meta/fetch/cross-origin-resource-policy/fetch.any.js.ini
+++ b/testing/web-platform/meta/fetch/cross-origin-resource-policy/fetch.any.js.ini
@@ -45,6 +45,7 @@
 
 
 [fetch.any.serviceworker.html]
+  disabled: https://bugzilla.mozilla.org/show_bug.cgi?id=1540914
   [Valid cross-origin no-cors fetch with a 'Cross-Origin-Resource-Policy: same-site' response header.]
     expected: FAIL
 
diff --git a/testing/web-platform/meta/html/dom/interfaces.https.html.ini b/testing/web-platform/meta/html/dom/interfaces.https.html.ini
index 392a5fb6eca3..073a88fb68c7 100644
--- a/testing/web-platform/meta/html/dom/interfaces.https.html.ini
+++ b/testing/web-platform/meta/html/dom/interfaces.https.html.ini
@@ -477,15 +477,6 @@ prefs: [dom.security.featurePolicy.enabled:true]
   [HTMLBodyElement interface: document.createElement("body") must inherit property "onunhandledrejection" with the proper type]
     expected: FAIL
 
-  [HTMLImageElement interface: operation decode()]
-    expected: FAIL
-
-  [HTMLImageElement interface: document.createElement("img") must inherit property "decode()" with the proper type]
-    expected: FAIL
-
-  [HTMLImageElement interface: new Image() must inherit property "decode()" with the proper type]
-    expected: FAIL
-
   [HTMLIFrameElement interface: attribute allowUserMedia]
     expected: FAIL
 
diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-iframe.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-iframe.html.ini
index d2289ddcbda6..48c489728cac 100644
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-iframe.html.ini
+++ b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-iframe.html.ini
@@ -1,20 +1,8 @@
 [image-decode-iframe.html]
-  expected:
-    ERROR
-  [(misc) Decode from removed iframe fails (loaded img)]
-    expected: TIMEOUT
-
-  [(misc) Decode from removed iframe fails (img not loaded)]
-    expected: NOTRUN
-
-  [(misc) Decode from iframe, later removed, fails (img not loaded)]
-    expected: NOTRUN
-
-  [HTMLImageElement.prototype.decode(), iframe tests. Decode from removed iframe fails (loaded img)]
-    expected: TIMEOUT
+  expected: TIMEOUT
 
   [HTMLImageElement.prototype.decode(), iframe tests. Decode from removed iframe fails (img not loaded)]
-    expected: NOTRUN
+    expected: TIMEOUT
 
   [HTMLImageElement.prototype.decode(), iframe tests. Decode from iframe, later removed, fails (img not loaded)]
     expected: NOTRUN
diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-path-changes-svg.tentative.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-path-changes-svg.tentative.html.ini
deleted file mode 100644
index c6ccbbea7362..000000000000
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-path-changes-svg.tentative.html.ini
+++ /dev/null
@@ -1,19 +0,0 @@
-[image-decode-path-changes-svg.tentative.html]
-  [SVGImageElement.prototype.decode(), href mutation tests. xlink:href changes fail decode.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), href mutation tests. href changes fail decode.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), href mutation tests. xlink:href changes fail decode; following good decode succeeds.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), href mutation tests. href changes fail decode; following good decode succeeds.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), href mutation tests. xlink:href changes fail decode; following bad decode fails.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), href mutation tests. href changes fail decode; following bad decode fails.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-path-changes.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-path-changes.html.ini
deleted file mode 100644
index d8bf52762725..000000000000
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-path-changes.html.ini
+++ /dev/null
@@ -1,49 +0,0 @@
-[image-decode-path-changes.html]
-  [(src) Path changes fail decode.]
-    expected: FAIL
-
-  [(src) Path changes fail decode; following good decode succeeds.]
-    expected: FAIL
-
-  [(src) Path changes fail decode; following bad decode fails.]
-    expected: FAIL
-
-  [(src) Path changes to the same path succeed.]
-    expected: FAIL
-
-  [(srcset) Path changes fail decode.]
-    expected: FAIL
-
-  [(srcset) Path changes fail decode; following good decode succeeds.]
-    expected: FAIL
-
-  [(srcset) Path changes fail decode; following bad decode fails.]
-    expected: FAIL
-
-  [(srcset) Path changes to the same path succeed.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), src/srcset mutation tests. src changes fail decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), src/srcset mutation tests. src changes fail decode; following good png decode succeeds.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), src/srcset mutation tests. src changes fail decode; following good svg decode succeeds.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), src/srcset mutation tests. src changes fail decode; following bad decode fails.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), src/srcset mutation tests. src changes to the same path succeed.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), src/srcset mutation tests. srcset changes fail decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), src/srcset mutation tests. srcset changes fail decode; following good decode succeeds.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), src/srcset mutation tests. srcset changes fail decode; following bad decode fails.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-picture.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-picture.html.ini
deleted file mode 100644
index 3e10b4957e4d..000000000000
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-picture.html.ini
+++ /dev/null
@@ -1,25 +0,0 @@
-[image-decode-picture.html]
-  [HTMLImageElement.prototype.decode(), picture tests. Image with PNG source decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), picture tests. Image with multiple sources decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), picture tests. Image with PNG data URL source decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), picture tests. Image with SVG source decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), picture tests. Non-existent source fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), picture tests. Corrupt image in src fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), picture tests. Image without srcset fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), picture tests. Multiple decodes for images with src succeed.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-svg.tentative.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-svg.tentative.html.ini
deleted file mode 100644
index be82788fa59d..000000000000
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-svg.tentative.html.ini
+++ /dev/null
@@ -1,40 +0,0 @@
-[image-decode-svg.tentative.html]
-  [SVGImageElement.prototype.decode(), basic tests. Image with PNG xlink:href decodes with undefined.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Image with PNG href decodes with undefined.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Image with PNG data URL xlink:href decodes with undefined.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Image with PNG data URL href decodes with undefined.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Image with SVG xlink:href decodes with undefined.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Image with SVG href decodes with undefined.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Non-existent xlink:href fails decode.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Non-existent href fails decode.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Corrupt image in xlink:href fails decode.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Corrupt image in href fails decode.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Image without xlink:href or href fails decode.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Multiple decodes with a xlink:href succeed.]
-    expected: FAIL
-
-  [SVGImageElement.prototype.decode(), basic tests. Multiple decodes with a href succeed.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-with-quick-attach-svg.tentative.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-with-quick-attach-svg.tentative.html.ini
deleted file mode 100644
index 07344310126b..000000000000
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-with-quick-attach-svg.tentative.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[image-decode-with-quick-attach-svg.tentative.html]
-  [SVGImageElement.prototype.decode(), attach to DOM before promise resolves.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-with-quick-attach.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-with-quick-attach.html.ini
deleted file mode 100644
index 27790990a427..000000000000
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode-with-quick-attach.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[image-decode-with-quick-attach.html]
-  [HTMLImageElement.prototype.decode(), attach to DOM before promise resolves.]
-    expected: FAIL
-
diff --git a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode.html.ini b/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode.html.ini
deleted file mode 100644
index 1abe9869734a..000000000000
--- a/testing/web-platform/meta/html/semantics/embedded-content/the-img-element/decode/image-decode.html.ini
+++ /dev/null
@@ -1,76 +0,0 @@
-[image-decode.html]
-  [(src) PNG image decodes with undefined.]
-    expected: FAIL
-
-  [(src) PNG url image decodes with undefined.]
-    expected: FAIL
-
-  [(src) SVG image decodes with undefined.]
-    expected: FAIL
-
-  [(src) Non-existent path fails decode.]
-    expected: FAIL
-
-  [(src) Corrupt image fails decode.]
-    expected: FAIL
-
-  [(src) Path-less image fails decode.]
-    expected: FAIL
-
-  [(src) Multiple decodes succeed.]
-    expected: FAIL
-
-  [(srcset) PNG image decodes with undefined.]
-    expected: FAIL
-
-  [(srcset) SVG image decodes with undefined.]
-    expected: FAIL
-
-  [(srcset) Non-existent path fails decode.]
-    expected: FAIL
-
-  [(srcset) Multiple decodes succeed.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Image with PNG src decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Image with PNG data URL src decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Image with SVG src decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Non-existent src fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Inactive document fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Adopted active image into inactive document fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Adopted inactive image into active document succeeds.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Corrupt image in src fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Image without src/srcset fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Multiple decodes for images with src succeed.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Image with PNG srcset decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Image with SVG srcset decodes with undefined.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Non-existent srcset fails decode.]
-    expected: FAIL
-
-  [HTMLImageElement.prototype.decode(), basic tests. Multiple decodes for images with srcset succeed.]
-    expected: FAIL
-
diff --git a/third_party/rust/gleam/.cargo-checksum.json b/third_party/rust/gleam/.cargo-checksum.json
index c912964f7684..1e2b6e94ce29 100644
--- a/third_party/rust/gleam/.cargo-checksum.json
+++ b/third_party/rust/gleam/.cargo-checksum.json
@@ -1 +1 @@
-{"files":{"COPYING":"ec82b96487e9e778ee610c7ab245162464782cfa1f555c2299333f8dbe5c036a","Cargo.toml":"5e823cb4a829b626b7b9b603dac4d3a98debf5e83b91897ab9f186eed8f49d61","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"62065228e42caebca7e7d7db1204cbb867033de5982ca4009928915e4095f3a3","README.md":"1acb12040be43a3582d5897f11870b3ffdcd7ce0f4f32de158175bb6b33ec0b7","build.rs":"6ee689b1edfcd469dea669b0dc11ca89e0172c3b58bb82ff7a58acc94e1f7e88","rustfmt.toml":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855","src/gl.rs":"e659b099df9c2ae39fc311aa649bbb8b96dfc7df8eba8f98b2eab34d5a368442","src/gl_fns.rs":"99693ea60d5867fea7d6f092e9fae6f2ff3d0be3c6f533257618261ccdfc6341","src/gles_fns.rs":"e28eadc5907dd963765574b21f68eb308674c7ec799b26896b86de9fee8c8eac","src/lib.rs":"16610c19b45a3f26d56b379a3591aa2e4fc9477e7bd88f86b31c6ea32e834861"},"package":"43edfa3a4321024d7dac1625cf154ef0c16996a6a384d066480e306ebd39fecc"}
\ No newline at end of file
+{"files":{"COPYING":"ec82b96487e9e778ee610c7ab245162464782cfa1f555c2299333f8dbe5c036a","Cargo.toml":"6bf850af90d5a3828cf26170a161f2ed06fa3cf3783dce79d28fe6444654408e","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"62065228e42caebca7e7d7db1204cbb867033de5982ca4009928915e4095f3a3","README.md":"1acb12040be43a3582d5897f11870b3ffdcd7ce0f4f32de158175bb6b33ec0b7","build.rs":"6ee689b1edfcd469dea669b0dc11ca89e0172c3b58bb82ff7a58acc94e1f7e88","rustfmt.toml":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855","src/gl.rs":"2663b598573f7521d06f878229eee65434c831cf9fd4b543b4fcdd3bb1b281aa","src/gl_fns.rs":"239ace5607ee8dd4bcad35db0c4908469d7deb4841c162f736e404e1403980f7","src/gles_fns.rs":"51f25388f092242fb25bfe4861e70690006f4ac28e854d709ebb440cbef3df03","src/lib.rs":"16610c19b45a3f26d56b379a3591aa2e4fc9477e7bd88f86b31c6ea32e834861"},"package":"39bb69499005e11b7b7cc0af38404a1bc0f53d954bffa8adcdb6e8d5b14f75d5"}
\ No newline at end of file
diff --git a/third_party/rust/gleam/Cargo.toml b/third_party/rust/gleam/Cargo.toml
index f5a9ca84c5ce..463fc70ee9ab 100644
--- a/third_party/rust/gleam/Cargo.toml
+++ b/third_party/rust/gleam/Cargo.toml
@@ -3,7 +3,7 @@
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
 # with all versions of Cargo and also rewrite `path` dependencies
-# to registry (e.g., crates.io) dependencies
+# to registry (e.g. crates.io) dependencies
 #
 # If you believe there's an error in this file please file an
 # issue against the rust-lang/cargo repository. If you're
@@ -12,7 +12,7 @@
 
 [package]
 name = "gleam"
-version = "0.6.15"
+version = "0.6.16"
 authors = ["The Servo Project Developers"]
 build = "build.rs"
 description = "Generated OpenGL bindings and wrapper for Servo."
diff --git a/third_party/rust/gleam/src/gl.rs b/third_party/rust/gleam/src/gl.rs
index 252ccfd51189..854b94abebaa 100644
--- a/third_party/rust/gleam/src/gl.rs
+++ b/third_party/rust/gleam/src/gl.rs
@@ -553,6 +553,9 @@ declare_gl_apis! {
     fn insert_event_marker_ext(&self, message: &str);
     fn push_group_marker_ext(&self, message: &str);
     fn pop_group_marker_ext(&self);
+    fn debug_message_insert_khr(&self, source: GLenum, type_: GLenum, id: GLuint, severity: GLenum, message: &str);
+    fn push_debug_group_khr(&self, source: GLenum, id: GLuint, message: &str);
+    fn pop_debug_group_khr(&self);
     fn fence_sync(&self, condition: GLenum, flags: GLbitfield) -> GLsync;
     fn client_wait_sync(&self, sync: GLsync, flags: GLbitfield, timeout: GLuint64);
     fn wait_sync(&self, sync: GLsync, flags: GLbitfield, timeout: GLuint64);
diff --git a/third_party/rust/gleam/src/gl_fns.rs b/third_party/rust/gleam/src/gl_fns.rs
index 62a3de0b73a4..851f6f639cc3 100644
--- a/third_party/rust/gleam/src/gl_fns.rs
+++ b/third_party/rust/gleam/src/gl_fns.rs
@@ -1946,6 +1946,32 @@ impl Gl for GlFns {
         }
     }
 
+    fn debug_message_insert_khr(&self, source: GLenum, type_: GLenum, id: GLuint, severity: GLenum, message: &str) {
+        if self.ffi_gl_.DebugMessageInsertKHR.is_loaded() {
+            unsafe {
+                self.ffi_gl_
+                    .DebugMessageInsertKHR(source, type_, id, severity, message.len() as GLsizei, message.as_ptr() as *const _);
+            }
+        }
+    }
+
+    fn push_debug_group_khr(&self, source: GLenum, id: GLuint, message: &str) {
+        if self.ffi_gl_.PushDebugGroupKHR.is_loaded() {
+            unsafe {
+                self.ffi_gl_
+                    .PushDebugGroupKHR(source, id, message.len() as GLsizei, message.as_ptr() as *const _);
+            }
+        }
+    }
+
+    fn pop_debug_group_khr(&self) {
+        if self.ffi_gl_.PopDebugGroupKHR.is_loaded() {
+            unsafe {
+                self.ffi_gl_.PopDebugGroupKHR();
+            }
+        }
+    }
+
     fn fence_sync(&self, condition: GLenum, flags: GLbitfield) -> GLsync {
         unsafe { self.ffi_gl_.FenceSync(condition, flags) as *const _ }
     }
diff --git a/third_party/rust/gleam/src/gles_fns.rs b/third_party/rust/gleam/src/gles_fns.rs
index 61c7bfb1e4a0..9877e4744f70 100644
--- a/third_party/rust/gleam/src/gles_fns.rs
+++ b/third_party/rust/gleam/src/gles_fns.rs
@@ -1952,6 +1952,32 @@ impl Gl for GlesFns {
         }
     }
 
+    fn debug_message_insert_khr(&self, source: GLenum, type_: GLenum, id: GLuint, severity: GLenum, message: &str) {
+        if self.ffi_gl_.DebugMessageInsertKHR.is_loaded() {
+            unsafe {
+                self.ffi_gl_
+                    .DebugMessageInsertKHR(source, type_, id, severity, message.len() as GLsizei, message.as_ptr() as *const _);
+            }
+        }
+    }
+
+    fn push_debug_group_khr(&self, source: GLenum, id: GLuint, message: &str) {
+        if self.ffi_gl_.PushDebugGroupKHR.is_loaded() {
+            unsafe {
+                self.ffi_gl_
+                    .PushDebugGroupKHR(source, id, message.len() as GLsizei, message.as_ptr() as *const _);
+            }
+        }
+    }
+
+    fn pop_debug_group_khr(&self) {
+        if self.ffi_gl_.PopDebugGroupKHR.is_loaded() {
+            unsafe {
+                self.ffi_gl_.PopDebugGroupKHR();
+            }
+        }
+    }
+
     fn fence_sync(&self, condition: GLenum, flags: GLbitfield) -> GLsync {
         unsafe { self.ffi_gl_.FenceSync(condition, flags) as *const _ }
     }
diff --git a/xpcom/base/ErrorList.py b/xpcom/base/ErrorList.py
index 680a12106ecc..baf6d41dae71 100755
--- a/xpcom/base/ErrorList.py
+++ b/xpcom/base/ErrorList.py
@@ -642,6 +642,11 @@ with modules["DOM"]:
     # decoding process.
     errors["NS_ERROR_DOM_JS_DECODING_ERROR"] = FAILURE(1026)
 
+    # Image decode errors.
+    errors["NS_ERROR_DOM_IMAGE_INACTIVE_DOCUMENT"] = FAILURE(1027)
+    errors["NS_ERROR_DOM_IMAGE_INVALID_REQUEST"] = FAILURE(1028)
+    errors["NS_ERROR_DOM_IMAGE_BROKEN"] = FAILURE(1029)
+
     # May be used to indicate when e.g. setting a property value didn't
     # actually change the value, like for obj.foo = "bar"; obj.foo = "bar";
     # the second assignment throws NS_SUCCESS_DOM_NO_OPERATION.