Adds a gfx_export.h to ui/gfx and converts all code in ui/gfx to

ui/gfx/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_GFX_SCREEN_H_
 #define UI_GFX_SCREEN_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
-#include "ui/base/ui_export.h"
 #include "ui/gfx/display.h"
+#include "ui/gfx/gfx_export.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/screen_type_delegate.h"
 
 namespace gfx {
 class DisplayObserver;
 class Rect;
 
 // A utility class for getting various info about screen size, displays,
 // cursor position, etc.
@@ skipping 62 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Screen);
 };
 
 Screen* CreateNativeScreen();
 
 }  // namespace gfx
 
 #endif  // UI_GFX_SCREEN_H_