Send array of paint rects and bitmaps as opposed to a Union

chrome/browser/renderer_host/render_widget_host.h

Index: chrome/browser/renderer_host/render_widget_host.h
===================================================================
--- chrome/browser/renderer_host/render_widget_host.h	(revision 17347)
+++ chrome/browser/renderer_host/render_widget_host.h	(working copy)
@@ -327,9 +327,10 @@
   void OnMsgShowPopup(const IPC::Message& message);
 
   // Paints the given bitmap to the current backing store at the given location.
-  void PaintBackingStoreRect(TransportDIB* dib,
-                             const gfx::Rect& bitmap_rect,
-                             const gfx::Size& view_size);
+  void PaintBackingStoreRects(TransportDIB* bitmap,
+                              const gfx::Rect& bitmap_rect,
+                              const std::vector<gfx::Rect>& paint_rects,
+                              const gfx::Size& view_size);
 
   // Scrolls the given |clip_rect| in the backing by the given dx/dy amount. The
   // |dib| and its corresponding location |bitmap_rect| in the backing store