Add decode() functionality to image elements.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 13 matching lines @@
 #ifndef HTMLImageElement_h
 #define HTMLImageElement_h
 
 #include "core/CoreExport.h"
 #include "core/html/FormAssociated.h"
 #include "core/html/HTMLElement.h"
 #include "core/html/HTMLImageLoader.h"
 #include "core/html/canvas/ImageElementBase.h"
 #include "platform/bindings/ActiveScriptWrappable.h"
 #include "platform/graphics/GraphicsTypes.h"
+#include "platform/heap/HeapAllocator.h"
 #include "platform/loader/fetch/FetchParameters.h"
 #include "platform/loader/fetch/ResourceResponse.h"
 
 namespace blink {
 
 class HTMLFormElement;
 class ImageCandidate;
 class ShadowRoot;
 
 class CORE_EXPORT HTMLImageElement final
@@ skipping 48 matching lines @@
   void setHeight(unsigned);
 
   KURL Src() const;
   void SetSrc(const String&);
 
   void setWidth(unsigned);
 
   int x() const;
   int y() const;
 
+  ScriptPromise decode(ScriptState*, ExceptionState&);
+
   bool complete() const;
 
   bool HasPendingActivity() const final {
     return GetImageLoader().HasPendingActivity();
   }
 
   bool CanContainRangeEndPoint() const override { return false; }
 
   const AtomicString ImageSourceURL() const override;
 
@@ skipping 14 matching lines @@
   void SetIsFallbackImage() { is_fallback_image_ = true; }
 
   FetchParameters::ResourceWidth GetResourceWidth();
   float SourceSize(Element&);
 
   void ForceReload() const;
 
   FormAssociated* ToFormAssociatedOrNull() override { return this; };
   void AssociateWith(HTMLFormElement*) override;
 
+  void ImageNotifyFinished(bool success);
+
  protected:
   // Controls how an image element appears in the layout. See:
   // https://html.spec.whatwg.org/multipage/embedded-content.html#image-request
   enum class LayoutDisposition : uint8_t {
     // Displayed as a partially or completely loaded image. Corresponds to the
     // `current request` state being: `unavailable`, `partially available`, or
     // `completely available`.
     kPrimaryContent,
     // Showing a broken image icon and 'alt' text, if any. Corresponds to the
     // `current request` being in the `broken` state.
@@ skipping 32 matching lines @@
 
   bool draggable() const override;
 
   InsertionNotificationRequest InsertedInto(ContainerNode*) override;
   void RemovedFrom(ContainerNode*) override;
   bool ShouldRegisterAsNamedItem() const override { return true; }
   bool ShouldRegisterAsExtraNamedItem() const override { return true; }
   bool IsInteractiveContent() const override;
   Image* ImageContents() override;
 
+  void RequestDecode();
+  void DidDecode(uint32_t sequence_id, bool success);

[pdr., 2017/05/18 03:20:10]

Can you add some short comments here and above RequestDecode?

Bikeshed: DecodeRequestFinished?

[vmpstr, 2017/05/18 18:51:13]

Done.

+
   void ResetFormOwner();
   ImageCandidate FindBestFitImageFromPictureParent();
   void SetBestFitURLAndDPRFromImageCandidate(const ImageCandidate&);
   HTMLImageLoader& GetImageLoader() const override { return *image_loader_; }
   void NotifyViewportChanged();
   void CreateMediaQueryListIfDoesNotExist();
 
   Member<HTMLImageLoader> image_loader_;
   Member<ViewportChangeListener> listener_;
   Member<HTMLFormElement> form_;
   AtomicString best_fit_image_url_;
   float image_device_pixel_ratio_;
   Member<HTMLSourceElement> source_;
   LayoutDisposition layout_disposition_;
+  HeapVector<Member<ScriptPromiseResolver>> decode_promise_resolvers_;
+  uint32_t decode_sequence_id_;
   unsigned form_was_set_by_parser_ : 1;
   unsigned element_created_by_parser_ : 1;
   unsigned is_fallback_image_ : 1;
 
   ReferrerPolicy referrer_policy_;
 };
 
 }  // namespace blink
 
 #endif  // HTMLImageElement_h