Remove the last references from production code to WebViewImpl.

third_party/WebKit/Source/web/WebViewImpl.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 85 matching lines @@
 class WebViewScheduler;
 
 class WEB_EXPORT WebViewImpl final
     : NON_EXPORTED_BASE(public WebViewBase),
       NON_EXPORTED_BASE(public WebGestureCurveTarget),
       public PageWidgetEventHandler,
       public WebScheduler::InterventionReporter,
       public WebViewScheduler::WebViewSchedulerSettings {
  public:
   static WebViewImpl* Create(WebViewClient*, WebPageVisibilityState);
-  static HashSet<WebViewImpl*>& AllInstances();
 
   // WebWidget methods:
   void Close() override;
   WebSize Size() override;
   void Resize(const WebSize&) override;
   void ResizeVisualViewport(const WebSize&) override;
   void DidEnterFullscreen() override;
   void DidExitFullscreen() override;
 
   void SetSuppressFrameRequestsWorkaroundFor704763Only(bool) override;
@@ skipping 630 matching lines @@
   Persistent<ResizeViewportAnchor> resize_viewport_anchor_;
 };
 
 // We have no ways to check if the specified WebView is an instance of
 // WebViewImpl because WebViewImpl is the only implementation of WebView.
 DEFINE_TYPE_CASTS(WebViewImpl, WebView, webView, true, true);
 
 }  // namespace blink
 
 #endif