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

chrome/renderer/extensions/tabs_custom_bindings.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/tabs_custom_bindings.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "content/public/renderer/render_view.h"
@@ skipping 14 matching lines @@
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   // Get the current RenderView so that we can send a routed IPC message from
   // the correct source.
   content::RenderView* renderview = context()->GetRenderView();
   if (!renderview)
     return;
 
   if (args.Length() >= 3 && args[0]->IsInt32() && args[1]->IsString() &&
       args[2]->IsString()) {
     int tab_id = args[0]->Int32Value();
-    std::string extension_id = *v8::String::Utf8Value(args[1]->ToString());
-    std::string channel_name = *v8::String::Utf8Value(args[2]->ToString());
+    std::string extension_id = *v8::String::Utf8Value(args[1]);
+    std::string channel_name = *v8::String::Utf8Value(args[2]);
     int port_id = -1;
     renderview->Send(new ExtensionHostMsg_OpenChannelToTab(
       renderview->GetRoutingID(), tab_id, extension_id, channel_name,
         &port_id));
     args.GetReturnValue().Set(static_cast<int32_t>(port_id));
     return;
   }
 }
 
 }  // namespace extensions