ImageResource: remove unnecessary vector copying during iteration.

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

Index: third_party/WebKit/Source/core/fetch/ImageResourceObserver.h
diff --git a/third_party/WebKit/Source/core/fetch/ImageResourceObserver.h b/third_party/WebKit/Source/core/fetch/ImageResourceObserver.h
index b1f5da8ede5cd434f9605d313c5444ec8011b99d..826a781a4ee24539dd6b0c0ff44f34d5411588d9 100644
--- a/third_party/WebKit/Source/core/fetch/ImageResourceObserver.h
+++ b/third_party/WebKit/Source/core/fetch/ImageResourceObserver.h
@@ -51,9 +51,13 @@ class CORE_EXPORT ImageResourceObserver {
   // 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.