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

ios/chrome/browser/ios_chrome_main_parts.h

 // Copyright 2016 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.
 
 #ifndef IOS_CHROME_BROWSER_IOS_CHROME_MAIN_PARTS_H_
 #define IOS_CHROME_BROWSER_IOS_CHROME_MAIN_PARTS_H_
 
+#include <memory>
+
 #include "base/command_line.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/metrics/field_trial.h"
 #include "ios/web/public/app/web_main_parts.h"
 
 class ApplicationContextImpl;
 class PrefService;
 
 namespace metrics {
 class TrackingSynchronizer;
 }
 
@@ skipping 18 matching lines @@
   // creation of field trials. Call only after labs have been converted to
   // switches.
   void SetUpMetricsAndFieldTrials();
 
   // Starts recording of metrics. This can only be called after we have a file
   // thread.
   void StartMetricsRecording();
 
   const base::CommandLine& parsed_command_line_;
 
-  scoped_ptr<ApplicationContextImpl> application_context_;
+  std::unique_ptr<ApplicationContextImpl> application_context_;
   scoped_refptr<metrics::TrackingSynchronizer> tracking_synchronizer_;
 
   // Statistical testing infrastructure for the entire browser. NULL until
   // SetUpMetricsAndFieldTrials is called.
-  scoped_ptr<base::FieldTrialList> field_trial_list_;
+  std::unique_ptr<base::FieldTrialList> field_trial_list_;
 
   PrefService* local_state_;
 
   // Initialized in SetupMetricsAndFieldTrials.
-  scoped_ptr<ios::FieldTrialSynchronizer> field_trial_synchronizer_;
+  std::unique_ptr<ios::FieldTrialSynchronizer> field_trial_synchronizer_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSChromeMainParts);
 };
 
 #endif  // IOS_CHROME_BROWSER_IOS_CHROME_MAIN_PARTS_H_