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

ui/aura/test/test_screen.h

 // 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 UI_AURA_TEST_TEST_SCREEN_H_
 #define UI_AURA_TEST_TEST_SCREEN_H_
 
 #include "base/compiler_specific.h"
-#include "ui/gfx/screen_impl.h"
+#include "ui/gfx/screen.h"
 
 namespace aura {
 class RootWindow;
 
 // A minimal, testing Aura implementation of gfx::Screen.
-class TestScreen : public gfx::ScreenImpl {
+class TestScreen : public gfx::Screen {
  public:
   explicit TestScreen(aura::RootWindow* root_window);
   virtual ~TestScreen();
 
  protected:
-  // gfx::ScreenImpl overrides:
+  // gfx::Screen overrides:
+  virtual bool IsDIPEnabled() OVERRIDE;
   virtual gfx::Point GetCursorScreenPoint() OVERRIDE;
   virtual gfx::NativeWindow GetWindowAtCursorScreenPoint() OVERRIDE;
   virtual int GetNumDisplays() OVERRIDE;
   virtual gfx::Display GetDisplayNearestWindow(
       gfx::NativeView view) const OVERRIDE;
   virtual gfx::Display GetDisplayNearestPoint(
       const gfx::Point& point) const OVERRIDE;
   virtual gfx::Display GetDisplayMatching(
       const gfx::Rect& match_rect) const OVERRIDE;
   virtual gfx::Display GetPrimaryDisplay() const OVERRIDE;
 
  private:
   gfx::Display GetMonitor() const;
 
   aura::RootWindow* root_window_;
 
   DISALLOW_COPY_AND_ASSIGN(TestScreen);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_TEST_TEST_SCREEN_H_