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

ios/chrome/browser/metrics/mobile_session_shutdown_metrics_provider.h

 // Copyright 2015 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_METRICS_MOBILE_SESSION_SHUTDOWN_METRICS_PROVIDER_H_
 #define IOS_CHROME_BROWSER_METRICS_MOBILE_SESSION_SHUTDOWN_METRICS_PROVIDER_H_
 
+#include <memory>
+
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "components/metrics/metrics_provider.h"
 
 namespace metrics {
 class MetricsService;
 }
 
 // Exposed for testing purposes only.
 // Values of the UMA Stability.MobileSessionShutdownType histogram.
 enum MobileSessionShutdownType {
   SHUTDOWN_IN_BACKGROUND = 0,
@@ skipping 34 matching lines @@
 
   // Whether there was a memory warning shortly before last shutdown.
   virtual bool ReceivedMemoryWarningBeforeLastShutdown();
 
  private:
   metrics::MetricsService* metrics_service_;
   DISALLOW_COPY_AND_ASSIGN(MobileSessionShutdownMetricsProvider);
 };
 
 #endif  // IOS_CHROME_BROWSER_METRICS_MOBILE_SESSION_SHUTDOWN_METRICS_PROVIDER_H_