Don't try to send automation message after the corresponding RV is gone

content/renderer/dom_automation_controller.h

 // 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.
 
 #ifndef CONTENT_RENDERER_DOM_AUTOMATION_CONTROLLER_H_
 #define CONTENT_RENDERER_DOM_AUTOMATION_CONTROLLER_H_
 
 #include "base/basictypes.h"
+#include "content/public/renderer/render_view_observer.h"
 #include "gin/wrappable.h"
 
 /* DomAutomationController class:
    Bound to Javascript window.domAutomationController object.
    At the very basic, this object makes any native value (string, numbers,
    boolean) from javascript available to the automation host in Cpp.
    Any renderer implementation that is built with this binding will allow the
    above facility.
    The intended use of this object is to expose the DOM Objects and their
    attributes to the automation host.
@@ skipping 54 matching lines @@
 namespace blink {
 class WebFrame;
 }
 
 namespace gin {
 class Arguments;
 }
 
 namespace content {
 
-class DomAutomationController : public gin::Wrappable<DomAutomationController> {
+class RenderViewImpl;
+
+class DomAutomationController : public gin::Wrappable<DomAutomationController>,
+                                public RenderViewObserver {
  public:
   static gin::WrapperInfo kWrapperInfo;
 
-  static void Install(blink::WebFrame* frame);
+  static void Install(RenderViewImpl* render_view, blink::WebFrame* frame);
 
   // Makes the renderer send a javascript value to the app.
   // The value to be sent can be either of type String,
   // Number (double casted to int32) or Boolean. Any other type or no
   // argument at all is ignored.
-  bool Send(const gin::Arguments& args);
+  bool SendMsg(const gin::Arguments& args);
 
   // Makes the renderer send a javascript value to the app.
   // The value should be properly formed JSON.
   bool SendJSON(const std::string& json);
 
   // Sends a string with a provided Automation Id.
   bool SendWithId(int automation_id, const std::string& str);
 
   bool SetAutomationId(int automation_id);
 
  private:
-  explicit DomAutomationController(blink::WebFrame* frame);
+  explicit DomAutomationController(RenderViewImpl* render_view);
   virtual ~DomAutomationController();
 
   // gin::WrappableBase
   virtual gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
       v8::Isolate* isolate) OVERRIDE;
 
-  blink::WebFrame* frame_;
+  // RenderViewObserver
+  virtual void OnDestruct() OVERRIDE;
 
   int automation_id_;  // routing id to be used by the next channel.
 
   DISALLOW_COPY_AND_ASSIGN(DomAutomationController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_DOM_AUTOMATION_CONTROLLER_H_