Refactor ViewsDelegate singleton

ui/views/controls/webview/webview.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/webview/webview.h"
 
 #include "content/public/browser/browser_accessibility_state.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/render_process_host.h"
@@ skipping 389 matching lines @@
 
 #if defined(OS_CHROMEOS)
   if (web_contents())
     NotifyAccessibilityEvent(ui::AX_EVENT_CHILDREN_CHANGED, false);
 #endif  // defined OS_CHROMEOS
 }
 
 content::WebContents* WebView::CreateWebContents(
       content::BrowserContext* browser_context) {
   content::WebContents* contents = NULL;
-  if (ViewsDelegate::views_delegate) {
-    contents = ViewsDelegate::views_delegate->CreateWebContents(
-        browser_context, NULL);
+  if (ViewsDelegate::GetInstance()) {
+    contents =
+        ViewsDelegate::GetInstance()->CreateWebContents(browser_context, NULL);
   }
 
   if (!contents) {
     content::WebContents::CreateParams create_params(
         browser_context, NULL);
     return content::WebContents::Create(create_params);
   }
 
   return contents;
 }
 
 }  // namespace views