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

extensions/renderer/api_request_handler.cc

 // 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.
 
 #include "extensions/renderer/api_request_handler.h"
 
 #include "base/bind.h"
 #include "base/guid.h"
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
@@ skipping 37 matching lines @@
   auto iter = pending_requests_.find(request_id);
   // The request may have been removed if the context was invalidated before a
   // response is ready.
   if (iter == pending_requests_.end())
     return;
 
   PendingRequest pending_request = std::move(iter->second);
   pending_requests_.erase(iter);
 
   v8::Isolate* isolate = pending_request.isolate;
+  v8::HandleScope handle_scope(isolate);
   v8::Local<v8::Context> context = pending_request.context.Get(isolate);
   std::unique_ptr<content::V8ValueConverter> converter(
       content::V8ValueConverter::create());
   std::vector<v8::Local<v8::Value>> args;
   args.reserve(response_args.GetSize());
   for (const auto& response : response_args)
     args.push_back(converter->ToV8Value(response.get(), context));
 
   // args.size() is converted to int, but args is controlled by chrome and is
   // never close to std::numeric_limits<int>::max.
@@ skipping 12 matching lines @@
 }
 
 std::set<int> APIRequestHandler::GetPendingRequestIdsForTesting() const {
   std::set<int> result;
   for (const auto& pair : pending_requests_)
     result.insert(pair.first);
   return result;
 }
 
 }  // namespace extensions