Convert //chrome/browser/chromeos from scoped_ptr to std::unique_ptr

chrome/browser/chromeos/file_manager/volume_manager.h

Index: chrome/browser/chromeos/file_manager/volume_manager.h
diff --git a/chrome/browser/chromeos/file_manager/volume_manager.h b/chrome/browser/chromeos/file_manager/volume_manager.h
index c6da5d202abf2d37333ad6c365280bcf12cbc630..6448d1109b282c96ea79c540f8983ce212e67111 100644
--- a/chrome/browser/chromeos/file_manager/volume_manager.h
+++ b/chrome/browser/chromeos/file_manager/volume_manager.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_CHROMEOS_FILE_MANAGER_VOLUME_MANAGER_H_
 
 #include <map>
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -14,7 +15,6 @@
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "chrome/browser/chromeos/drive/drive_integration_service.h"
@@ -311,7 +311,7 @@ class VolumeManager : public KeyedService,
       file_system_provider_service_;  // Not owned by this class.
   GetMtpStorageInfoCallback get_mtp_storage_info_callback_;
   std::map<std::string, linked_ptr<Volume>> mounted_volumes_;
-  scoped_ptr<SnapshotManager> snapshot_manager_;
+  std::unique_ptr<SnapshotManager> snapshot_manager_;
 
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.