Fix the content_browsertests everywhere maybe.

ui/gfx/screen_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 "ui/gfx/screen_win.h"
 
 #include <windows.h>
 
 #include "base/logging.h"
 #include "ui/gfx/display.h"
@@ skipping 39 matching lines @@
   HWND window_hwnd = GetCursorPos(&location) ? WindowFromPoint(location) : NULL;
   return GetNativeWindowFromHWND(window_hwnd);
 }
 
 int ScreenWin::GetNumDisplays() {
   return GetSystemMetrics(SM_CMONITORS);
 }
 
 gfx::Display ScreenWin::GetDisplayNearestWindow(gfx::NativeView window) const {
   HWND window_hwnd = GetHWNDFromNativeView(window);
+  if (!window_hwnd) {
+    // When |window| isn't rooted to a display, we should just return the
+    // default display so we get some correct display information like the
+    // scaling factor.
+    return GetPrimaryDisplay();
+  }
+
   MONITORINFO monitor_info;
   monitor_info.cbSize = sizeof(monitor_info);
   GetMonitorInfo(MonitorFromWindow(window_hwnd, MONITOR_DEFAULTTONEAREST),
                  &monitor_info);
   return GetDisplay(monitor_info);
 }
 
 gfx::Display ScreenWin::GetDisplayNearestPoint(const gfx::Point& point) const {
   POINT initial_loc = { point.x(), point.y() };
   HMONITOR monitor = MonitorFromPoint(initial_loc, MONITOR_DEFAULTTONEAREST);
@@ skipping 46 matching lines @@
 #endif  // USE_AURA
 }
 
 #if !defined(USE_AURA)
 Screen* CreateNativeScreen() {
   return new ScreenWin;
 }
 #endif  // !USE_AURA
 
 }  // namespace gfx