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

ui/aura/test/test_screen.h

Index: ui/aura/test/test_screen.h
diff --git a/ui/aura/test/test_screen.h b/ui/aura/test/test_screen.h
index 9363368df4cc056c53a90f5ff8b58066b043b67e..ca5524c9923fd3c49f420a81d0864c74b8ded951 100644
--- a/ui/aura/test/test_screen.h
+++ b/ui/aura/test/test_screen.h
@@ -6,19 +6,20 @@
 #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;