Switch SupportsUserData uses to use unique_ptr.

ios/clean/chrome/app/steps/launch_to_background.mm

 // 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.
 
 #import "ios/clean/chrome/app/steps/launch_to_background.h"
 
 #include <memory>
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/foundation_util.h"
@@ skipping 60 matching lines @@
 - (BOOL)canRunInState:(ApplicationState*)state {
   return state.phase == APPLICATION_BASIC;
 }
 
 - (void)runInState:(ApplicationState*)state {
   web::SetWebClient(new ChromeWebClient());
 
   // Create and persist an IOSChromeMain instance.
   state.persistentState->SetUserData(
       kChromeMainKey,
-      new ChromeMainContainer(base::MakeUnique<IOSChromeMain>()));
+      base::MakeUnique<ChromeMainContainer>(base::MakeUnique<IOSChromeMain>()));
 
   // Add a step to the termination steps of |state| that will stop and remove
   // the IOSChromeMain instance.
   [[state terminationSteps] addObject:[[StopChromeMain alloc] init]];
 
   state.phase = APPLICATION_BACKGROUNDED;
 }
 
 @end
 
@@ skipping 26 matching lines @@
          state.phase == APPLICATION_BACKGROUNDED;
 }
 
 - (void)runInState:(ApplicationState*)state {
   state.browserState = GetApplicationContext()
                            ->GetChromeBrowserStateManager()
                            ->GetLastUsedBrowserState();
 }
 
 @end