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

extensions/renderer/api_binding_hooks.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_HOOKS_H_
 #define EXTENSIONS_RENDERER_API_BINDING_HOOKS_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 45 matching lines @@
                            const std::string& api_name);
 
   // Looks for a custom hook to handle the given request and, if one exists,
   // runs it. Returns true if a hook was found and run.
   bool HandleRequest(const std::string& api_name,
                      const std::string& method_name,
                      v8::Local<v8::Context> context,
                      const APISignature* signature,
                      gin::Arguments* arguments);
 
+  // Returns a JS interface that can be used to register hooks.
+  v8::Local<v8::Object> GetJSHookInterface(const std::string& api_name,
+                                           v8::Local<v8::Context> context);
+
  private:
   // Whether we've tried to use any hooks associated with this object.
   bool hooks_used_ = false;
 
   // All registered request handlers.
   std::map<std::string, HandleRequestHook> request_hooks_;
 
   // The script to run to initialize JS hooks, if any.
   v8::Global<v8::String> js_hooks_source_;
 
   // The name of the JS resource for the hooks. Used to create a ScriptOrigin
   // to make exception stack traces more readable.
   v8::Global<v8::String> js_resource_name_;
 
   binding::RunJSFunction run_js_;
 
   DISALLOW_COPY_AND_ASSIGN(APIBindingHooks);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_API_BINDING_HOOKS_H_