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 97e42b416212186afda835f7cd97bbd916118818..aac88e885a68c60907bd64eab9bdc8b4d2398922 100644
--- a/third_party/WebKit/Source/core/html/HTMLImageElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLImageElement.h
@@ -99,6 +99,8 @@ class CORE_EXPORT HTMLImageElement final
   int x() const;
   int y() const;
 
+  ScriptPromise decode(ScriptState*, ExceptionState&);
+
   bool complete() const;
 
   bool hasPendingActivity() const final {
@@ -177,6 +179,8 @@ class CORE_EXPORT HTMLImageElement final
   void didAddUserAgentShadowRoot(ShadowRoot&) override;
   PassRefPtr<ComputedStyle> customStyleForLayoutObject() override;
 
+  void defaultEventHandler(Event*) override;
+
  private:
   bool areAuthorShadowsAllowed() const override { return false; }
 
@@ -212,6 +216,9 @@ 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;
@@ -222,8 +229,11 @@ class CORE_EXPORT HTMLImageElement final
   unsigned m_formWasSetByParser : 1;
   unsigned m_elementCreatedByParser : 1;
   unsigned m_isFallbackImage : 1;
+  Member<ScriptPromiseResolver> m_decodePromiseResolver;
 
   ReferrerPolicy m_referrerPolicy;
+
+  WTF::WeakPtrFactory<HTMLImageElement> m_weakPtrFactory;
 };
 
 }  // namespace blink