remove some calls to to-be-deprecated v8::Value::To* functions

extensions/renderer/v8_context_native_handler.cc

 // Copyright 2014 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/v8_context_native_handler.h"
 
 #include "base/bind.h"
 #include "extensions/common/features/feature.h"
 #include "extensions/renderer/dispatcher.h"
 #include "extensions/renderer/script_context.h"
@@ skipping 14 matching lines @@
   RouteFunction(
       "RunWithNativesEnabledModuleSystem",
       base::Bind(&V8ContextNativeHandler::RunWithNativesEnabledModuleSystem,
                  base::Unretained(this)));
 }
 
 void V8ContextNativeHandler::GetAvailability(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK_EQ(args.Length(), 1);
   v8::Isolate* isolate = args.GetIsolate();
-  std::string api_name = *v8::String::Utf8Value(args[0]->ToString());
+  std::string api_name = *v8::String::Utf8Value(args[0]);
   Feature::Availability availability = context_->GetAvailability(api_name);
 
   v8::Handle<v8::Object> ret = v8::Object::New(isolate);
   ret->Set(v8::String::NewFromUtf8(isolate, "is_available"),
            v8::Boolean::New(isolate, availability.is_available()));
   ret->Set(v8::String::NewFromUtf8(isolate, "message"),
            v8::String::NewFromUtf8(isolate, availability.message().c_str()));
   ret->Set(v8::String::NewFromUtf8(isolate, "result"),
            v8::Integer::New(isolate, availability.result()));
   args.GetReturnValue().Set(ret);
@@ skipping 16 matching lines @@
   CHECK(args[0]->IsFunction());
   v8::Handle<v8::Value> call_with_args[] = {
     context()->module_system()->NewInstance()
   };
   ModuleSystem::NativesEnabledScope natives_enabled(context()->module_system());
   context()->CallFunction(
       v8::Handle<v8::Function>::Cast(args[0]), 1, call_with_args);
 }
 
 }  // namespace extensions