Attempt to fix ChromeFrameTestWithWebServer tests.

chrome/browser/ui/window_snapshot/window_snapshot.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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_UI_WINDOW_SNAPSHOT_WINDOW_SNAPSHOT_H_
 #define CHROME_BROWSER_UI_WINDOW_SNAPSHOT_WINDOW_SNAPSHOT_H_
 #pragma once
 
 #include <vector>
 
 #include "ui/gfx/native_widget_types.h"
 
 namespace gfx {
   class Rect;
 }
 
 namespace browser {
 
 // Grabs a snapshot of the rectangle area |snapshot_bounds| with respect to the
 // top left corner of the designated window and stores a PNG representation
-// into a byte vector. Returns true if the operation is successful.
+// into a byte vector. On Windows, |window| may be NULL to grab a snapshot of
+// the primary monitor. Returns true if the operation is successful.
 bool GrabWindowSnapshot(gfx::NativeWindow window,
                         std::vector<unsigned char>* png_representation,
                         const gfx::Rect& snapshot_bounds);
 
 }  // namespace browser
 
 #endif  // CHROME_BROWSER_UI_WINDOW_SNAPSHOT_WINDOW_SNAPSHOT_H_