Use actual value of display scale factor from GetMonitorScaleFactor().

ui/views/win/hwnd_message_handler.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 "ui/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 #include <tchar.h>
@@ skipping 1400 matching lines @@
   // set at the current scale factor and may cause the window to display too
   // soon. See http://crbug.com/625076.
   int dpi = LOWORD(w_param);
   if (dpi_ == dpi)
     return 0;
 
   dpi_ = dpi;
   SetBoundsInternal(gfx::Rect(*reinterpret_cast<RECT*>(l_param)), false);
   delegate_->HandleWindowScaleFactorChanged(
       display::win::GetScalingFactorFromDPI(dpi_));
+
+  LOG(ERROR) << "HWNDMessageHandler::OnDpiChanged(" << dpi << ")";
   return 0;
 }
 
 void HWNDMessageHandler::OnEnterMenuLoop(BOOL from_track_popup_menu) {
   if (menu_depth_++ == 0)
     delegate_->HandleMenuLoop(true);
 }
 
 void HWNDMessageHandler::OnEnterSizeMove() {
   delegate_->HandleBeginWMSizeMove();
@@ skipping 1282 matching lines @@
   MONITORINFO monitor_info = {sizeof(monitor_info)};
   GetMonitorInfo(MonitorFromWindow(hwnd(), MONITOR_DEFAULTTOPRIMARY),
                  &monitor_info);
   gfx::Rect shrunk_rect(monitor_info.rcMonitor);
   shrunk_rect.set_height(shrunk_rect.height() - 1);
   background_fullscreen_hack_ = true;
   SetBoundsInternal(shrunk_rect, false);
 }
 
 }  // namespace views