Refactor ViewsDelegate singleton

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>
 
@@ skipping 839 matching lines @@
 void HWNDMessageHandler::DispatchKeyEventPostIME(const ui::KeyEvent& key) {
   SetMsgHandled(delegate_->HandleKeyEvent(key));
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // HWNDMessageHandler, gfx::WindowImpl overrides:
 
 HICON HWNDMessageHandler::GetDefaultWindowIcon() const {
   if (use_system_default_icon_)
     return nullptr;
-  return ViewsDelegate::views_delegate
-             ? ViewsDelegate::views_delegate->GetDefaultWindowIcon()
+  return ViewsDelegate::GetInstance()
+             ? ViewsDelegate::GetInstance()->GetDefaultWindowIcon()
              : nullptr;
 }
 
 HICON HWNDMessageHandler::GetSmallWindowIcon() const {
   if (use_system_default_icon_)
     return nullptr;
-  return ViewsDelegate::views_delegate
-             ? ViewsDelegate::views_delegate->GetSmallWindowIcon()
+  return ViewsDelegate::GetInstance()
+             ? ViewsDelegate::GetInstance()->GetSmallWindowIcon()
              : nullptr;
 }
 
 LRESULT HWNDMessageHandler::OnWndProc(UINT message,
                                       WPARAM w_param,
                                       LPARAM l_param) {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
   tracked_objects::ScopedTracker tracking_profile1(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "440919 HWNDMessageHandler::OnWndProc1"));
@@ skipping 110 matching lines @@
       gfx::Point(CR_GET_X_LPARAM(l_param), CR_GET_Y_LPARAM(l_param)));
   *handled = IsMsgHandled();
   return ret;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // HWNDMessageHandler, private:
 
 int HWNDMessageHandler::GetAppbarAutohideEdges(HMONITOR monitor) {
   autohide_factory_.InvalidateWeakPtrs();
-  return ViewsDelegate::views_delegate ?
-      ViewsDelegate::views_delegate->GetAppbarAutohideEdges(
-          monitor,
-          base::Bind(&HWNDMessageHandler::OnAppbarAutohideEdgesChanged,
-                     autohide_factory_.GetWeakPtr())) :
-      ViewsDelegate::EDGE_BOTTOM;
+  return ViewsDelegate::GetInstance()
+             ? ViewsDelegate::GetInstance()->GetAppbarAutohideEdges(
+                   monitor,
+                   base::Bind(&HWNDMessageHandler::OnAppbarAutohideEdgesChanged,
+                              autohide_factory_.GetWeakPtr()))
+             : ViewsDelegate::EDGE_BOTTOM;
 }
 
 void HWNDMessageHandler::OnAppbarAutohideEdgesChanged() {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "440919 HWNDMessageHandler::OnAppbarAutohideEdgesChanged"));
 
   // This triggers querying WM_NCCALCSIZE again.
   RECT client;
@@ skipping 1720 matching lines @@
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_HIDEWINDOW);
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_SHOWWINDOW);
   }
   // WM_DWMCOMPOSITIONCHANGED is only sent to top level windows, however we want
   // to notify our children too, since we can have MDI child windows who need to
   // update their appearance.
   EnumChildWindows(hwnd(), &SendDwmCompositionChanged, NULL);
 }
 
 }  // namespace views