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

chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.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 "chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.h"
 
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/host/ash_remote_window_tree_host_win.h"
 #include "ash/shell.h"
@@ skipping 16 matching lines @@
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/env_vars.h"
 #include "components/search_engines/util.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/gpu_data_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/page_navigator.h"
 #include "content/public/browser/web_contents.h"
 #include "ui/aura/remote_window_tree_host_win.h"
-#include "ui/gfx/win/dpi.h"
+#include "ui/gfx/dpi.h"
 #include "ui/metro_viewer/metro_viewer_messages.h"
 #include "url/gurl.h"
 
 namespace {
 
 void CloseOpenAshBrowsers() {
   BrowserList* browser_list =
       BrowserList::GetInstance(chrome::HOST_DESKTOP_TYPE_ASH);
   if (browser_list) {
     for (BrowserList::const_iterator i = browser_list->begin();
@@ skipping 113 matching lines @@
 void ChromeMetroViewerProcessHost::OnWindowSizeChanged(uint32 width,
                                                        uint32 height) {
   std::vector<ash::DisplayInfo> info_list;
   info_list.push_back(ash::DisplayInfo::CreateFromSpec(
       base::StringPrintf("%dx%d*%f", width, height, gfx::GetDPIScale())));
   ash::Shell::GetInstance()->display_manager()->OnNativeDisplaysChanged(
       info_list);
   aura::RemoteWindowTreeHostWin::Instance()->HandleWindowSizeChanged(width,
                                                                      height);
 }