mac: History swiping doesn't work right with iframes.

content/browser/renderer_host/render_widget_host_view_base.h

Index: content/browser/renderer_host/render_widget_host_view_base.h
diff --git a/content/browser/renderer_host/render_widget_host_view_base.h b/content/browser/renderer_host/render_widget_host_view_base.h
index e00c9779946bcb76624a076f3917032e4c628acc..25c9c0e681cc0e6a67000a0378e7951a8627d956 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.h
+++ b/content/browser/renderer_host/render_widget_host_view_base.h
@@ -80,9 +80,12 @@ class CONTENT_EXPORT RenderWidgetHostViewBase : public RenderWidgetHostView,
   // IPC::Listener implementation:
   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
 
-  // Called when a mousewheel event was not processed by the renderer.
+  // Called after the renderer has ACKed a mousewheel event. |consumed|
+  // reflects whether the event was consumed by the renderer or the render
+  // widget host's delegate.
   // virtual for testing.
-  virtual void UnhandledWheelEvent(const blink::WebMouseWheelEvent& event);
+  virtual void ProcessedWheelEvent(const blink::WebMouseWheelEvent& event,
+                                   bool consumed);
 
   // Called by the host when the input flush has completed.
   void OnDidFlushInput();