Fix crash when destroying a RenderWidgetHost that holds the pointer

content/browser/frame_host/cross_process_frame_connector.h

 // Copyright 2014 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_CROSS_PROCESS_FRAME_CONNECTOR_H_
 #define CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
 
 #include <stdint.h>
 
 #include "cc/output/compositor_frame.h"
@@ skipping 95 matching lines @@
 
   // Determines whether the root RenderWidgetHostView (and thus the current
   // page) has focus.
   bool HasFocus();
   // Focuses the root RenderWidgetHostView.
   void FocusRootView();
 
   // Locks the mouse. Returns true if mouse is locked.
   bool LockMouse();
 
+  // Unlocks the mouse if the mouse is locked.
+  void UnlockMouse();
+
   // Returns the parent RenderWidgetHostView or nullptr it it doesn't have one.
   virtual RenderWidgetHostViewBase* GetParentRenderWidgetHostView();
 
   // Returns the view for the top-level frame under the same WebContents.
   RenderWidgetHostViewBase* GetRootRenderWidgetHostView();
 
   // Exposed for tests.
   RenderWidgetHostViewBase* GetRootRenderWidgetHostViewForTesting() {
     return GetRootRenderWidgetHostView();
   }
@@ skipping 19 matching lines @@
   RenderWidgetHostViewChildFrame* view_;
 
   gfx::Rect child_frame_rect_;
   float device_scale_factor_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_