Introduce XGetImage() for GrabWindowSnapshot() in ChromeOS.

ui/aura/root_window_host_win.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_host_win.h"
 
 #include <windows.h>
 
 #include <algorithm>
 
@@ skipping 249 matching lines @@
   return gfx::Point(max(0, min(size.width(), static_cast<int>(pt.x))),
                     max(0, min(size.height(), static_cast<int>(pt.y))));
 }
 
 bool RootWindowHostWin::ConfineCursorToRootWindow() {
   RECT window_rect;
   GetWindowRect(hwnd(), &window_rect);
   return ClipCursor(&window_rect) != 0;
 }
 
+bool RootWindowHostWin::GrabSnapshot(
+    const gfx::Rect& snapshot_bounds,
+    std::vector<unsigned char>* png_representation) {
+  NOTIMPLEMENTED();
+  return false;
+}
+
 void RootWindowHostWin::UnConfineCursor() {
   ClipCursor(NULL);
 }
 
 void RootWindowHostWin::MoveCursorTo(const gfx::Point& location) {
   POINT pt;
   ClientToScreen(hwnd(), &pt);
   SetCursorPos(pt.x, pt.y);
 }
 
@@ skipping 49 matching lines @@
 }
 
 void RootWindowHostWin::OnSize(UINT param, const CSize& size) {
   // Minimizing resizes the window to 0x0 which causes our layout to go all
   // screwy, so we just ignore it.
   if (param != SIZE_MINIMIZED)
     root_window_->OnHostResized(gfx::Size(size.cx, size.cy));
 }
 
 }  // namespace aura