[Extensions Bindings] Add a bridge to use current custom bindings

extensions/renderer/api_binding.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_BINDING_H_
 #define EXTENSIONS_RENDERER_API_BINDING_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 57 matching lines @@
              ArgumentSpec::RefMap* type_refs);
   ~APIBinding();
 
   // Returns a new v8::Object for the API this APIBinding represents.
   v8::Local<v8::Object> CreateInstance(
       v8::Local<v8::Context> context,
       v8::Isolate* isolate,
       APIEventHandler* event_handler,
       const AvailabilityCallback& is_available);
 
+  // Returns the JS interface to use when registering hooks with legacy custom
+  // bindings.
+  v8::Local<v8::Object> GetJSHookInterface(v8::Local<v8::Context> context);
+
  private:
   // Handles a call an API method with the given |name| and matches the
   // arguments against |signature|.
   void HandleCall(const std::string& name,
                   const APISignature* signature,
                   gin::Arguments* args);
 
   // The root name of the API, e.g. "tabs" for chrome.tabs.
   std::string api_name_;
 
   // A map from method name to expected signature.
   std::map<std::string, std::unique_ptr<APISignature>> signatures_;
 
   // The names of all events associated with this API.
   std::vector<std::string> event_names_;
 
   // The callback to use when an API is invoked with valid arguments.
   APIMethodCallback method_callback_;
 
-  // The registered hooks for this API. Null if there are no registered custom
-  // hooks.
+  // The registered hooks for this API.
   std::unique_ptr<APIBindingHooks> binding_hooks_;
 
   // The reference map for all known types; required to outlive this object.
   const ArgumentSpec::RefMap* type_refs_;
 
   base::WeakPtrFactory<APIBinding> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(APIBinding);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_API_BINDING_H_