Add context to gfx::Screen calls in support of simultaneous desktop+ash

ui/aura/desktop/desktop_screen_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/desktop/desktop_screen_win.h"
 
 #include "base/logging.h"
 #include "ui/aura/desktop/desktop_screen.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/root_window_host.h"
@@ skipping 22 matching lines @@
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopScreenWin, public:
 
 DesktopScreenWin::DesktopScreenWin() {
 }
 
 DesktopScreenWin::~DesktopScreenWin() {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// DesktopScreenWin, gfx::ScreenImpl implementation:
+// DesktopScreenWin, gfx::Screen implementation:
+
+bool DesktopScreenWin::IsDIPEnabled() {
+  return true;
+}
 
 gfx::Point DesktopScreenWin::GetCursorScreenPoint() {
   POINT pt;
   GetCursorPos(&pt);
   return gfx::Point(pt);
 }
 
 gfx::NativeWindow DesktopScreenWin::GetWindowAtCursorScreenPoint() {
   POINT location;
   gfx::AcceleratedWidget accelerated_widget =
@@ skipping 40 matching lines @@
   MONITORINFO mi = GetMonitorInfoForMonitor(
       MonitorFromWindow(NULL, MONITOR_DEFAULTTOPRIMARY));
   gfx::Display display = GetDisplay(mi);
   DCHECK_EQ(GetSystemMetrics(SM_CXSCREEN), display.size().width());
   DCHECK_EQ(GetSystemMetrics(SM_CYSCREEN), display.size().height());
   return display;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-gfx::ScreenImpl* CreateDesktopScreen() {
+gfx::Screen* CreateDesktopScreen() {
   return new DesktopScreenWin;
 }
 
 }  // namespace aura