Move the event attach/detach logic on unload from event.js to

extensions/renderer/module_system.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 EXTENSIONS_RENDERER_MODULE_SYSTEM_H_
 #define EXTENSIONS_RENDERER_MODULE_SYSTEM_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 124 matching lines @@
                           const std::string& field,
                           const std::string& module_name,
                           const std::string& module_field);
 
   // Passes exceptions to |handler| rather than console::Fatal.
   void SetExceptionHandlerForTest(scoped_ptr<ExceptionHandler> handler) {
     exception_handler_ = handler.Pass();
   }
 
  protected:
+  friend class ModuleSystemTest;
   friend class ScriptContext;
   void Invalidate() override;
 
  private:
   typedef std::map<std::string, linked_ptr<NativeHandler> > NativeHandlerMap;
 
   // Retrieves the lazily defined field specified by |property|.
   static void LazyFieldGetter(v8::Local<v8::String> property,
                               const v8::PropertyCallbackInfo<v8::Value>& info);
   // Retrieves the lazily defined field specified by |property| on a native
@@ skipping 70 matching lines @@
   std::set<std::string> overridden_native_handlers_;
 
   base::WeakPtrFactory<ModuleSystem> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ModuleSystem);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_MODULE_SYSTEM_H_