For OSX, make it so that notifications only start resizing after the first paint is done.

chrome/browser/notifications/balloon_host.h

 // Copyright (c) 2010 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 CHROME_BROWSER_NOTIFICATIONS_BALLOON_HOST_H_
 #define CHROME_BROWSER_NOTIFICATIONS_BALLOON_HOST_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 94 matching lines @@
   virtual void UpdatePreferredSize(const gfx::Size& pref_size);
   virtual RendererPreferences GetRendererPrefs(Profile* profile) const;
 
   // Enable DOM UI. This has to be called before renderer is created.
   void EnableDOMUI();
 
   virtual void UpdateInspectorSetting(const std::string& key,
                                       const std::string& value);
   virtual void ClearInspectorSettings();
 
+  // Called when the render view has painted.
+  void RenderWidgetHostDidPaint();
+
  protected:
   virtual ~BalloonHost();
   // Must override in platform specific implementations.
   virtual void InitRenderWidgetHostView() = 0;
   virtual RenderWidgetHostView* render_widget_host_view() const = 0;
 
   // Owned pointer to the host for the renderer process.
   RenderViewHost* render_view_host_;
 
  private:
@@ skipping 20 matching lines @@
 
   // Handles requests to extension APIs. Will only be non-NULL if we are
   // rendering a page from an extension.
   scoped_ptr<ExtensionFunctionDispatcher> extension_function_dispatcher_;
 
   // A flag to enable DOM UI.
   bool enable_dom_ui_;
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_BALLOON_HOST_H_