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

chrome/browser/renderer_host/render_widget_host.h

 // Copyright (c) 2009 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_RENDERER_HOST_RENDER_WIDGET_HOST_H_
 #define CHROME_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_H_
 
 #include <queue>
 #include <vector>
 
@@ skipping 309 matching lines @@
   void OnMsgInputEventAck(const IPC::Message& message);
   void OnMsgFocus();
   void OnMsgBlur();
   void OnMsgSetCursor(const WebCursor& cursor);
   // Using int instead of ViewHostMsg_ImeControl for control's type to avoid
   // having to bring in render_messages.h in a header file.
   void OnMsgImeUpdateStatus(int control, const gfx::Rect& caret_rect);
   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
   // is the newly painted pixels by the renderer.
   void ScrollBackingStoreRect(TransportDIB* dib,
                               const gfx::Rect& bitmap_rect,
                               int dx, int dy,
                               const gfx::Rect& clip_rect,
                               const gfx::Size& view_size);
 
@@ skipping 81 matching lines @@
 
   // Set when we cancel updating the text direction.
   // This flag also ignores succeeding update requests until we call
   // NotifyTextDirection().
   bool text_direction_canceled_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHost);
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_H_