Refactor ViewsDelegate singleton

ui/views/controls/menu/menu_controller.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/controls/menu/menu_controller.h"
 
 #include "base/i18n/case_conversion.h"
 #include "base/i18n/rtl.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
@@ skipping 343 matching lines @@
       // notification when the drag has finished.
       StartCancelAllTimer();
     }
     return NULL;
   }
 
   if (button)
     pressed_lock_.reset(new MenuButton::PressedLock(button));
 
   // Make sure Chrome doesn't attempt to shut down while the menu is showing.
-  if (ViewsDelegate::views_delegate)
-    ViewsDelegate::views_delegate->AddRef();
+  if (ViewsDelegate::GetInstance())
+    ViewsDelegate::GetInstance()->AddRef();
 
   // We need to turn on nestable tasks as in some situations (pressing alt-f for
   // one) the menus are run from a task. If we don't do this and are invoked
   // from a task none of the tasks we schedule are processed and the menu
   // appears totally broken.
   message_loop_depth_++;
   DCHECK_LE(message_loop_depth_, 2);
   RunMessageLoop(nested_menu);
   message_loop_depth_--;
 
-  if (ViewsDelegate::views_delegate)
-    ViewsDelegate::views_delegate->ReleaseRef();
+  if (ViewsDelegate::GetInstance())
+    ViewsDelegate::GetInstance()->ReleaseRef();
 
   // Close any open menus.
   SetSelection(NULL, SELECTION_UPDATE_IMMEDIATELY | SELECTION_EXIT);
 
 #if defined(OS_WIN)
   // On Windows, if we select the menu item by touch and if the window at the
   // location is another window on the same thread, that window gets a
   // WM_MOUSEACTIVATE message and ends up activating itself, which is not
   // correct. We workaround this by setting a property on the window at the
   // current cursor location. We check for this property in our
@@ skipping 1730 matching lines @@
 
   gfx::Screen* screen = gfx::Screen::GetScreenFor(native_view);
   gfx::NativeWindow window = screen->GetWindowAtScreenPoint(screen_loc);
 
 #if defined(OS_WIN)
   // Convert screen_loc to pixels for the Win32 API's like WindowFromPoint,
   // PostMessage/SendMessage to work correctly. These API's expect the
   // coordinates to be in pixels.
   // PostMessage() to metro windows isn't allowed (access will be denied). Don't
   // try to repost with Win32 if the window under the mouse press is in metro.
-  if (!ViewsDelegate::views_delegate ||
-      !ViewsDelegate::views_delegate->IsWindowInMetro(window)) {
+  if (!ViewsDelegate::GetInstance() ||
+      !ViewsDelegate::GetInstance()->IsWindowInMetro(window)) {
     gfx::Point screen_loc_pixels = gfx::win::DIPToScreenPoint(screen_loc);
     HWND target_window = window ? HWNDForNativeWindow(window) :
                                   WindowFromPoint(screen_loc_pixels.ToPOINT());
     HWND source_window = HWNDForNativeView(native_view);
     if (!target_window || !source_window ||
         GetWindowThreadProcessId(source_window, NULL) !=
         GetWindowThreadProcessId(target_window, NULL)) {
       // Even though we have mouse capture, windows generates a mouse event if
       // the other window is in a separate thread. Only repost an event if
       // |target_window| and |source_window| were created on the same thread,
@@ skipping 217 matching lines @@
   }
 }
 
 gfx::Screen* MenuController::GetScreen() {
   Widget* root = owner_ ? owner_->GetTopLevelWidget() : NULL;
   return root ? gfx::Screen::GetScreenFor(root->GetNativeView())
               : gfx::Screen::GetNativeScreen();
 }
 
 }  // namespace views