Convert //ios from scoped_ptr to std::unique_ptr.

ios/web/app/web_main_runner.mm

 // 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 "ios/web/app/web_main_runner.h"
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/i18n/icu_util.h"
 #include "base/logging.h"
@@ skipping 94 matching lines @@
 
   // True if basic startup was completed.
   bool completed_basic_startup_;
 
   // The delegate will outlive this object.
   WebMainDelegate* delegate_;
 
   // Used if the embedder doesn't set one.
   WebClient empty_web_client_;
 
-  scoped_ptr<base::AtExitManager> exit_manager_;
-  scoped_ptr<WebMainLoop> main_loop_;
+  std::unique_ptr<base::AtExitManager> exit_manager_;
+  std::unique_ptr<WebMainLoop> main_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMainRunnerImpl);
 };
 
 // static
 WebMainRunner* WebMainRunner::Create() {
   return new WebMainRunnerImpl();
 }
 
 }  // namespace web