Combine ViewHostMsg_{Paint,Scroll}Rect into one IPC....

chrome/browser/renderer_host/backing_store_win.cc

 // 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.
 
 #include "chrome/browser/renderer_host/backing_store.h"
 
 #include "app/gfx/gdi_util.h"
 #include "base/command_line.h"
 #include "chrome/browser/renderer_host/render_widget_host.h"
 #include "chrome/common/chrome_switches.h"
@@ skipping 128 matching lines @@
                     paint_rect.width(),
                     paint_rect.height(),
                     paint_rect.x() - bitmap_rect.x(),
                     paint_rect.y() - bitmap_rect.y(),
                     paint_rect.width(),
                     paint_rect.height(),
                     bitmap->memory(),
                     reinterpret_cast<BITMAPINFO*>(&hdr));
 }
 
-void BackingStore::ScrollRect(base::ProcessHandle process,
-                              TransportDIB* bitmap,
-                              const gfx::Rect& bitmap_rect,
-                              int dx, int dy,
+void BackingStore::ScrollRect(int dx, int dy,
                               const gfx::Rect& clip_rect,
                               const gfx::Size& view_size) {
   RECT damaged_rect, r = clip_rect.ToRECT();
   ScrollDC(hdc_, dx, dy, NULL, &r, NULL, &damaged_rect);
 
   // TODO(darin): this doesn't work if dx and dy are both non-zero!
   DCHECK(dx == 0 || dy == 0);
-
-  // We expect that damaged_rect should equal bitmap_rect.
-  DCHECK(gfx::Rect(damaged_rect) == bitmap_rect);
-
-  PaintRect(process, bitmap, bitmap_rect, bitmap_rect);
 }