Add decode() functionality to image elements.

third_party/WebKit/Source/core/exported/WebViewBase.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.#ifndef WebViewBase_h
 
 #ifndef WebViewBase_h
 #define WebViewBase_h
 
 #include "core/page/EventWithHitTestResults.h"
 #include "platform/transforms/TransformationMatrix.h"
 #include "platform/wtf/RefCounted.h"
@@ skipping 107 matching lines @@
   virtual void DidUpdateFullscreenSize() = 0;
   virtual void SetLastHiddenPagePopup(WebPagePopupImpl*) = 0;
   virtual WebInputEventResult SendContextMenuEvent(const WebKeyboardEvent&) = 0;
 
   virtual WebSpellCheckClient* SpellCheckClient() = 0;
 
   virtual CompositorAnimationTimeline* LinkHighlightsTimeline() const = 0;
 
   virtual WebSettingsImpl* SettingsImpl() = 0;
 
+  virtual void RequestDecode(
+      sk_sp<SkImage>,
+      std::unique_ptr<WTF::Function<void(bool)>> callback) = 0;
+
   using WebWidget::GetPagePopup;
   virtual PagePopup* OpenPagePopup(PagePopupClient*) = 0;
   virtual void ClosePagePopup(PagePopup*) = 0;
   virtual void CleanupPagePopup() = 0;
   virtual LocalDOMWindow* PagePopupWindow() const = 0;
 
   virtual void InvalidateRect(const IntRect&) = 0;
 
   // These functions only apply to the main frame.
   //
@@ skipping 81 matching lines @@
   virtual void EnableTapHighlightAtPoint(
       const GestureEventWithHitTestResults& targeted_tap_event) = 0;
   virtual LinkHighlightImpl* GetLinkHighlight(int) = 0;
   virtual unsigned NumLinkHighlights() = 0;
   virtual void EnableTapHighlights(HeapVector<Member<Node>>&) = 0;
   virtual void SetCurrentInputEventForTest(const WebInputEvent*) = 0;
 };
 }
 
 #endif