Fix crash when destroying a RenderWidgetHost that holds the pointer

content/browser/frame_host/cross_process_frame_connector.cc

 // 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.
 
 #include "content/browser/frame_host/cross_process_frame_connector.h"
 
 #include "cc/surfaces/surface.h"
 #include "cc/surfaces/surface_manager.h"
 #include "content/browser/compositor/surface_utils.h"
 #include "content/browser/frame_host/frame_tree.h"
@@ skipping 185 matching lines @@
     root_view->Focus();
 }
 
 bool CrossProcessFrameConnector::LockMouse() {
   RenderWidgetHostViewBase* root_view = GetRootRenderWidgetHostView();
   if (root_view)
     return root_view->LockMouse();
   return false;
 }
 
+void CrossProcessFrameConnector::UnlockMouse() {
+  RenderWidgetHostViewBase* root_view = GetRootRenderWidgetHostView();
+  if (root_view)
+    root_view->UnlockMouse();
+}
+
 void CrossProcessFrameConnector::OnForwardInputEvent(
     const blink::WebInputEvent* event) {
   if (!view_)
     return;
 
   RenderFrameHostManager* manager =
       frame_proxy_in_parent_renderer_->frame_tree_node()->render_manager();
   RenderWidgetHostImpl* parent_widget =
       manager->ForInnerDelegate()
           ? manager->GetOuterRenderWidgetHostForKeyboardInput()
@@ skipping 124 matching lines @@
 
   if (parent) {
     return static_cast<RenderWidgetHostViewBase*>(
         parent->current_frame_host()->GetView());
   }
 
   return nullptr;
 }
 
 }  // namespace content