ImageResource: remove unnecessary vector copying during iteration.

third_party/WebKit/Source/core/fetch/ImageResourceObserver.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007 Apple 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 33 matching lines @@
 
   // Called just after imageChanged() if all image data is received or errored.
   // TODO(hiroshige): Merge imageNotifyFinished() into imageChanged().
   virtual void imageNotifyFinished(ImageResource*) {}
 
   // Called to find out if this client wants to actually display the image. Used
   // to tell when we can halt animation. Content nodes that hold image refs for
   // example would not render the image, but LayoutImages would (assuming they
   // have visibility: visible and their layout tree isn't hidden e.g., in the
   // b/f cache or in a background tab).
+  //
+  // An implementation of this method is not allowed to add or remove
+  // ImageResource observers.
   virtual bool willRenderImage() { return false; }
 
-  // Called to get imageAnimation policy from settings
+  // Called to get imageAnimation policy from settings. An implementation of
+  // this method is not allowed to add or remove ImageResource observers.
   virtual bool getImageAnimationPolicy(ImageAnimationPolicy&) { return false; }
 
   virtual ResourcePriority computeResourcePriority() const {

[yhirano, 2016/12/08 07:29:21]

This function has the same restriction.

[sof, 2016/12/08 07:32:51]

Done.

     return ResourcePriority();
   }
 
   // Name for debugging, e.g. shown in memory-infra.
   virtual String debugName() const = 0;
 
   static bool isExpectedType(ImageResourceObserver*) { return true; }
 };
 
 }  // namespace blink
 
 #endif