Support optional arguments in SendRequestNatives::StartRequest

chrome/renderer/extensions/send_request_natives.cc

 // Copyright (c) 2012 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 "chrome/renderer/extensions/send_request_natives.h"
 
 #include "base/json/json_reader.h"
 #include "content/public/renderer/v8_value_converter.h"
 #include "chrome/renderer/extensions/extension_request_sender.h"
 
@@ skipping 23 matching lines @@
 // Starts an API request to the browser, with an optional callback.  The
 // callback will be dispatched to EventBindings::HandleResponse.
 v8::Handle<v8::Value> SendRequestNatives::StartRequest(
     const v8::Arguments& args) {
   std::string name = *v8::String::AsciiValue(args[0]);
   int request_id = args[2]->Int32Value();
   bool has_callback = args[3]->BooleanValue();
   bool for_io_thread = args[4]->BooleanValue();
 
   scoped_ptr<V8ValueConverter> converter(V8ValueConverter::create());
+  converter->SetUndefinedAllowed(true);  // Allow passing optional values.
   scoped_ptr<Value> value_args(
       converter->FromV8Value(args[1], v8::Context::GetCurrent()));
   if (!value_args.get() || !value_args->IsType(Value::TYPE_LIST)) {
     NOTREACHED() << "Unable to convert args passed to StartRequest";
     return v8::Undefined();
   }
 
   request_sender_->StartRequest(name, request_id, has_callback, for_io_thread,
                                 static_cast<ListValue*>(value_args.get()));
   return v8::Undefined();
 }
 
 }  // namespace extensions