Change snasphotting API to take in a bounds Rect

chrome/browser/ui/window_snapshot/window_snapshot_aura.cc

 // Copyright (c) 2011 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/ui/window_snapshot/window_snapshot.h"
 
 #include "base/logging.h"
 #include "ui/gfx/rect.h"
 
 namespace browser {
 
 gfx::Rect GrabWindowSnapshot(gfx::NativeWindow window_handle,
-                             std::vector<unsigned char>* png_representation) {
+                             std::vector<unsigned char>* png_representation,
+                             const gfx::Rect snapshot_bounds) {
   // TODO(saintlou): Stub for Aura.
   NOTIMPLEMENTED();
   return gfx::Rect();
 }
 
 }  // namespace browser