Add mayHaveChangedRenderedSize callback.

content/renderer/render_view.h

 // Copyright (c) 2011 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 CONTENT_RENDERER_RENDER_VIEW_H_
 #define CONTENT_RENDERER_RENDER_VIEW_H_
 #pragma once
 
 #include <deque>
 #include <map>
@@ skipping 526 matching lines @@
   virtual void didDestroyScriptContext(WebKit::WebFrame* frame);
   virtual void didCreateIsolatedScriptContext(WebKit::WebFrame* frame);
   virtual void logCrossFramePropertyAccess(
       WebKit::WebFrame* frame,
       WebKit::WebFrame* target,
       bool cross_origin,
       const WebKit::WebString& property_name,
       unsigned long long event_id);
   virtual void didChangeContentsSize(WebKit::WebFrame* frame,
                                      const WebKit::WebSize& size);
+  virtual void mayHaveChangedRenderedSize(WebKit::WebFrame* frame);
   virtual void didChangeScrollOffset(WebKit::WebFrame* frame);
   virtual void reportFindInPageMatchCount(int request_id,
                                           int count,
                                           bool final_update);
   virtual void reportFindInPageSelection(int request_id,
                                          int active_match_ordinal,
                                          const WebKit::WebRect& sel);
 
   virtual void openFileSystem(WebKit::WebFrame* frame,
                               WebKit::WebFileSystem::Type type,
@@ skipping 466 matching lines @@
 
   // Cache the preferred size of the page in order to prevent sending the IPC
   // when layout() recomputes but doesn't actually change sizes.
   gfx::Size preferred_size_;
 
   // Nasty hack. WebKit does not send us events when the preferred size changes,
   // so we must poll it. See also:
   // https://bugs.webkit.org/show_bug.cgi?id=32807.
   base::RepeatingTimer<RenderView> preferred_size_change_timer_;
 
+  // Used to delay determining the preferred size (to avoid intermediate
+  // states for the sizes).
+  base::OneShotTimer<RenderView> check_preferred_size_timer_;
+
 #if defined(OS_MACOSX)
   // Track the fake plugin window handles allocated on the browser side for
   // the accelerated compositor and (currently) accelerated plugins so that
   // we can discard them when the view goes away.
   std::set<gfx::PluginWindowHandle> fake_plugin_window_handles_;
 #endif
 
   // Plugins -------------------------------------------------------------------
 
   // Remember the first uninstalled plugin, so that we can ask the plugin
@@ skipping 106 matching lines @@
   // bunch of stuff, you should probably create a helper class and put your
   // data and methods on that to avoid bloating RenderView more.  You can use
   // the Observer interface to filter IPC messages and receive frame change
   // notifications.
   // ---------------------------------------------------------------------------
 
   DISALLOW_COPY_AND_ASSIGN(RenderView);
 };
 
 #endif  // CONTENT_RENDERER_RENDER_VIEW_H_