[Extensions Bindings] Notify of event unregistration on invalidation

extensions/renderer/api_bindings_system.h

 // Copyright 2016 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_API_BINDINGS_SYSTEM_H_
 #define EXTENSIONS_RENDERER_API_BINDINGS_SYSTEM_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 65 matching lines @@
   // is, maybe we should rethink this. Downside would be that it's less
   // efficient to register multiple hooks for the same API.
   APIBindingHooks* GetHooksForAPI(const std::string& api_name);
 
   // Registers the handler for creating a custom type with the given
   // |type_name|, where |type_name| is the fully-qualified type (e.g.
   // storage.StorageArea).
   void RegisterCustomType(const std::string& type_name,
                           const CustomTypeHandler& function);
 
+  // Handles any cleanup necessary before releasing the given |context|.
+  void WillReleaseContext(v8::Local<v8::Context> context);
+
   APIRequestHandler* request_handler() { return &request_handler_; }
   APITypeReferenceMap* type_reference_map() { return &type_reference_map_; }
 
  private:
   // Creates a new APIBinding for the given |api_name|.
   std::unique_ptr<APIBinding> CreateNewAPIBinding(const std::string& api_name);
 
   // Callback for the APITypeReferenceMap in order to initialize an unknown
   // type.
   void InitializeType(const std::string& name);
@@ skipping 30 matching lines @@
   // The method to retrieve the DictionaryValue describing a given extension
   // API. Curried in for testing purposes so we can use fake APIs.
   GetAPISchemaMethod get_api_schema_;
 
   DISALLOW_COPY_AND_ASSIGN(APIBindingsSystem);
 };
 
 }  // namespace
 
 #endif  // EXTENSIONS_RENDERER_API_BINDINGS_SYSTEM_H_