Stop sending events and messages to content script contexts after their

chrome/renderer/extensions/chrome_v8_context_set.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 CHROME_RENDERER_EXTENSIONS_CHROME_V8_CONTEXT_SET_H_
 #define CHROME_RENDERER_EXTENSIONS_CHROME_V8_CONTEXT_SET_H_
 
 #include <set>
 #include <string>
 
@@ skipping 51 matching lines @@
   // Calls chromeHidden.<methodName> in each context for <extension_id>. If
   // render_view is non-NULL, only call the function in contexts belonging to
   // that view. The called javascript function should not return a value other
   // than v8::Undefined(). A DCHECK is setup to break if it is otherwise.
   void DispatchChromeHiddenMethod(const std::string& extension_id,
                                   const std::string& method_name,
                                   const base::ListValue& arguments,
                                   content::RenderView* render_view,
                                   const GURL& event_url) const;
 
+  // Cleans up contexts belonging to an unloaded extension.
+  void OnExtensionUnloaded(const std::string& extension_id);
+
  private:
   ContextSet contexts_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeV8ContextSet);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_RENDERER_EXTENSIONS_CHROME_V8_CONTEXT_SET_H_