Refactor ViewsDelegate singleton

ui/views/widget/widget_delegate.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/widget/widget_delegate.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/views/bubble/bubble_delegate.h"
 #include "ui/views/view.h"
@@ skipping 98 matching lines @@
   return false;
 }
 
 std::string WidgetDelegate::GetWindowName() const {
   return std::string();
 }
 
 void WidgetDelegate::SaveWindowPlacement(const gfx::Rect& bounds,
                                          ui::WindowShowState show_state) {
   std::string window_name = GetWindowName();
-  if (!ViewsDelegate::views_delegate || window_name.empty())
+  if (!ViewsDelegate::GetInstance() || window_name.empty())
     return;
 
-  ViewsDelegate::views_delegate->SaveWindowPlacement(
-      GetWidget(), window_name, bounds, show_state);
+  ViewsDelegate::GetInstance()->SaveWindowPlacement(GetWidget(), window_name,
+                                                    bounds, show_state);
 }
 
 bool WidgetDelegate::GetSavedWindowPlacement(
     const Widget* widget,
     gfx::Rect* bounds,
     ui::WindowShowState* show_state) const {
   std::string window_name = GetWindowName();
-  if (!ViewsDelegate::views_delegate || window_name.empty())
+  if (!ViewsDelegate::GetInstance() || window_name.empty())
     return false;
 
-  return ViewsDelegate::views_delegate->GetSavedWindowPlacement(
+  return ViewsDelegate::GetInstance()->GetSavedWindowPlacement(
       widget, window_name, bounds, show_state);
 }
 
 bool WidgetDelegate::ShouldRestoreWindowSize() const {
   return true;
 }
 
 View* WidgetDelegate::GetContentsView() {
   if (!default_contents_view_)
     default_contents_view_ = new View;
@@ skipping 58 matching lines @@
 
 const Widget* WidgetDelegateView::GetWidget() const {
   return View::GetWidget();
 }
 
 const char* WidgetDelegateView::GetClassName() const {
   return kViewClassName;
 }
 
 }  // namespace views