Introduce XGetImage() for GrabWindowSnapshot() in ChromeOS.

ui/aura/root_window.cc

 // 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.
 
 #include "ui/aura/root_window.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 514 matching lines @@
 scoped_refptr<CompositorLock> RootWindow::GetCompositorLock() {
   if (!compositor_lock_)
     compositor_lock_ = new CompositorLock(this);
   return compositor_lock_;
 }
 
 void RootWindow::SetFocusWhenShown(bool focused) {
   host_->SetFocusWhenShown(focused);
 }
 
+bool RootWindow::GrabSnapshot(std::vector<unsigned char>* png_representation,
+                              const gfx::Rect& snapshot_bounds) {
+  DCHECK(bounds().Contains(snapshot_bounds));
+  return host_->GrabSnapshot(png_representation, snapshot_bounds);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // RootWindow, Window overrides:
 
 RootWindow* RootWindow::GetRootWindow() {
   return this;
 }
 
 const RootWindow* RootWindow::GetRootWindow() const {
   return this;
 }
@@ skipping 478 matching lines @@
 void RootWindow::UnlockCompositor() {
   DCHECK(compositor_lock_);
   compositor_lock_ = NULL;
   if (draw_on_compositor_unlock_) {
     draw_on_compositor_unlock_ = false;
     ScheduleDraw();
   }
 }
 
 }  // namespace aura