Enable hidpi on Linux, refactor a bit on Windows to share

win8/metro_driver/direct3d_helper.cc

 // Copyright 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 "stdafx.h"
 #include <corewindow.h>
 #include <windows.applicationmodel.core.h>
 #include <windows.graphics.display.h>
 
 #include "win8/metro_driver/direct3d_helper.h"
 #include "base/logging.h"
 #include "base/win/windows_version.h"
-#include "ui/gfx/win/dpi.h"
+#include "ui/gfx/dpi.h"
 #include "win8/metro_driver/winrt_utils.h"
 
 namespace {
 
 void CheckIfFailed(HRESULT hr) {
   DCHECK(!FAILED(hr));
   if (FAILED(hr))
     DVLOG(0) << "Direct3D call failed, hr = " << hr;
 }
 
@@ skipping 131 matching lines @@
       // Prevent DXGI from monitoring an application message queue and thus
       // attempt mode changes. For e.g. Alt + Enter by default causes
       // DXGI to attempt to take the window fullscreen.
       CheckIfFailed(dxgi_factory->MakeWindowAssociation(
           window, DXGI_MWA_NO_WINDOW_CHANGES));
     }
   }
 }
 
 }  // namespace metro_driver