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

chrome/browser/ui/views/frame/minimize_button_metrics_win.cc

 // 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.
 
 #include "chrome/browser/ui/views/frame/minimize_button_metrics_win.h"
 
 #include "base/logging.h"
 #include "base/i18n/rtl.h"
 #include "ui/base/win/shell.h"
-#include "ui/gfx/win/dpi.h"
+#include "ui/gfx/dpi.h"
 
 namespace {
 
 int GetMinimizeButtonOffsetForWindow(HWND hwnd) {
   // The WM_GETTITLEBARINFOEX message can fail if we are not active/visible. By
   // fail we get a location of 0; the return status code is always the same and
   // similarly the state never seems to change (titlebar_info.rgstate).
   TITLEBARINFOEX titlebar_info = {0};
   titlebar_info.cbSize = sizeof(TITLEBARINFOEX);
   SendMessage(hwnd, WM_GETTITLEBARINFOEX, 0,
               reinterpret_cast<WPARAM>(&titlebar_info));
 
   if (titlebar_info.rgrect[2].left == titlebar_info.rgrect[2].right ||
       (titlebar_info.rgstate[2] & (STATE_SYSTEM_INVISIBLE |
                                    STATE_SYSTEM_OFFSCREEN |
                                    STATE_SYSTEM_UNAVAILABLE))) {
     return 0;
   }
 
   // WM_GETTITLEBARINFOEX returns rects in screen coordinates in pixels.
   // We need to convert the minimize button corner offset to DIP before
   // returning it.
   POINT minimize_button_corner = { titlebar_info.rgrect[2].left, 0 };
   MapWindowPoints(HWND_DESKTOP, hwnd, &minimize_button_corner, 1);
-  return minimize_button_corner.x / gfx::win::GetDeviceScaleFactor();
+  return minimize_button_corner.x / gfx::GetDeviceScaleFactor();
 }
 
 }  // namespace
 
 // static
 int MinimizeButtonMetrics::last_cached_minimize_button_x_delta_ = 0;
 
 MinimizeButtonMetrics::MinimizeButtonMetrics()
     : hwnd_(NULL),
       cached_minimize_button_x_delta_(last_cached_minimize_button_x_delta_),
@@ skipping 49 matching lines @@
     cached_minimize_button_x_delta_ = minimize_button_offset;
   } else {
     RECT client_rect = {0};
     GetClientRect(hwnd_, &client_rect);
     cached_minimize_button_x_delta_ =
         client_rect.right - minimize_button_offset;
   }
   last_cached_minimize_button_x_delta_ = cached_minimize_button_x_delta_;
   return minimize_button_offset;
 }