Add decode() functionality to image elements.

third_party/WebKit/Source/core/html/HTMLImageElement.h

Index: third_party/WebKit/Source/core/html/HTMLImageElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLImageElement.h b/third_party/WebKit/Source/core/html/HTMLImageElement.h
index f4a5c8c901d8695641345da02626b0bb2929f7e4..6cea32f7aec3f94003495ed58f22686af5762702 100644
--- a/third_party/WebKit/Source/core/html/HTMLImageElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLImageElement.h
@@ -32,6 +32,7 @@
 #include "core/html/canvas/CanvasImageElementSource.h"
 #include "core/imagebitmap/ImageBitmapSource.h"
 #include "platform/graphics/GraphicsTypes.h"
+#include "platform/heap/HeapAllocator.h"
 #include "platform/loader/fetch/FetchRequest.h"
 #include "platform/loader/fetch/ResourceResponse.h"
 
@@ -99,6 +100,8 @@ class CORE_EXPORT HTMLImageElement final
   int x() const;
   int y() const;
 
+  ScriptPromise decode(ScriptState*, ExceptionState&);
+
   bool complete() const;
 
   bool hasPendingActivity() const final {
@@ -166,6 +169,8 @@ class CORE_EXPORT HTMLImageElement final
   void didAddUserAgentShadowRoot(ShadowRoot&) override;
   PassRefPtr<ComputedStyle> customStyleForLayoutObject() override;
 
+  void defaultEventHandler(Event*) override;
+
  private:
   bool areAuthorShadowsAllowed() const override { return false; }
 
@@ -201,6 +206,9 @@ class CORE_EXPORT HTMLImageElement final
   void notifyViewportChanged();
   void createMediaQueryListIfDoesNotExist();
 
+  void requestDecode();
+  void didDecode(bool success);
+
   Member<HTMLImageLoader> m_imageLoader;
   Member<ViewportChangeListener> m_listener;
   Member<HTMLFormElement> m_form;
@@ -211,8 +219,11 @@ class CORE_EXPORT HTMLImageElement final
   unsigned m_formWasSetByParser : 1;
   unsigned m_elementCreatedByParser : 1;
   unsigned m_isFallbackImage : 1;
+  HeapVector<Member<ScriptPromiseResolver>> m_decodePromiseResolvers;
 
   ReferrerPolicy m_referrerPolicy;
+
+  WTF::WeakPtrFactory<HTMLImageElement> m_weakPtrFactory;
 };
 
 }  // namespace blink