[Content] Update V8ValueConverter::create to return a std::unique_ptr

extensions/renderer/guest_view/mime_handler_view/mime_handler_view_container.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/guest_view/mime_handler_view/mime_handler_view_container.h"
 
 #include <map>
 #include <set>
 
 #include "base/macros.h"
@@ skipping 250 matching lines @@
 
 void MimeHandlerViewContainer::PostMessageFromValue(
     const base::Value& message) {
   blink::WebFrame* frame = render_frame()->GetWebFrame();
   if (!frame)
     return;
 
   v8::Isolate* isolate = v8::Isolate::GetCurrent();
   v8::HandleScope handle_scope(isolate);
   v8::Context::Scope context_scope(frame->MainWorldScriptContext());
-  std::unique_ptr<content::V8ValueConverter> converter(
-      content::V8ValueConverter::create());
-  PostMessage(isolate,
-              converter->ToV8Value(&message, frame->MainWorldScriptContext()));
+  PostMessage(isolate, content::V8ValueConverter::Create()->ToV8Value(
+                           &message, frame->MainWorldScriptContext()));
 }
 
 void MimeHandlerViewContainer::OnCreateMimeHandlerViewGuestACK(
     int element_instance_id) {
   DCHECK_NE(this->element_instance_id(), guest_view::kInstanceIDNone);
   DCHECK_EQ(this->element_instance_id(), element_instance_id);
 
   if (!render_frame())
     return;
 
@@ skipping 42 matching lines @@
   if (!render_frame())
     return;
 
   render_frame()->Send(
       new ExtensionsGuestViewHostMsg_CreateMimeHandlerViewGuest(
           render_frame()->GetRoutingID(), view_id_, element_instance_id(),
           element_size_));
 }
 
 }  // namespace extensions