Fix crash when destroying a RenderWidgetHost that holds the pointer

content/browser/frame_host/interstitial_page_impl.h

 // Copyright 2013 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.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 100 matching lines @@
   void UpdateTitle(RenderFrameHost* render_frame_host,
                    int32_t page_id,
                    const base::string16& title,
                    base::i18n::TextDirection title_direction) override;
   InterstitialPage* GetAsInterstitialPage() override;
   AccessibilityMode GetAccessibilityMode() const override;
   void Cut() override;
   void Copy() override;
   void Paste() override;
   void SelectAll() override;
+  bool HasMouseLock(RenderWidgetHostImpl* render_widget_host) override;
 
   // RenderViewHostDelegate implementation:
   RenderViewHostDelegateView* GetDelegateView() override;
   bool OnMessageReceived(RenderViewHost* render_view_host,
                          const IPC::Message& message) override;
   const GURL& GetMainFrameLastCommittedURL() const override;
   void RenderViewTerminated(RenderViewHost* render_view_host,
                             base::TerminationStatus status,
                             int error_code) override;
   RendererPreferences GetRendererPrefs(
@@ skipping 171 matching lines @@
   scoped_refptr<SessionStorageNamespace> session_storage_namespace_;
 
   base::WeakPtrFactory<InterstitialPageImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InterstitialPageImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_