Implement "iframe shim" behavior for windowed plugins....

chrome/renderer/webplugin_delegate_proxy.h

Index: chrome/renderer/webplugin_delegate_proxy.h
===================================================================
--- chrome/renderer/webplugin_delegate_proxy.h	(revision 2783)
+++ chrome/renderer/webplugin_delegate_proxy.h	(working copy)
@@ -52,7 +52,9 @@
   virtual bool Initialize(const GURL& url, char** argn, char** argv, int argc,
                           WebPlugin* plugin, bool load_manually);
   virtual void UpdateGeometry(const gfx::Rect& window_rect,
-                              const gfx::Rect& clip_rect, bool visible);
+                              const gfx::Rect& clip_rect,
+                              const std::vector<gfx::Rect>& cutout_rects,
+                              bool visible);
   virtual void Paint(HDC hdc, const gfx::Rect& rect);
   virtual void Print(HDC hdc);
   virtual NPObject* GetPluginScriptableObject();
@@ -157,6 +159,7 @@
 
   gfx::Rect plugin_rect_;
   gfx::Rect deferred_clip_rect_;
+  std::vector<gfx::Rect> deferred_cutout_rects_;
   bool send_deferred_update_geometry_;
   bool visible_;