Add ui::GrabDesktopSnapshot for Windows.

ui/snapshot/snapshot_desktop.h

+// Copyright 2013 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 UI_SNAPSHOT_SNAPSHOT_DESKTOP_H_
+#define UI_SNAPSHOT_SNAPSHOT_DESKTOP_H_
+
+#include <vector>
+
+namespace gfx {
+class Rect;
+}
+
+namespace ui {
+
+// Grabs a snapshot of the desktop. No security checks are done.  This is
+// intended to be used for debugging purposes where no BrowserProcess instance
+// is available (ie. tests). DO NOT use in a result of user action.
+bool GrabDesktopSnapshot(
+    std::vector<unsigned char>* png_representation,

[sky, 2013/04/22 16:25:19]

style guide says out params are last.

[grt (UTC plus 2), 2013/04/22 19:14:03]

Done.

+    const gfx::Rect& snapshot_bounds);
+
+}  // namespace ui
+
+#endif  // UI_SNAPSHOT_SNAPSHOT_DESKTOP_H_