Switch SupportsUserData uses to use unique_ptr.

ios/chrome/browser/tabs/tab_model_list.mm

 // Copyright 2017 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/chrome/browser/tabs/tab_model_list.h"
 
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
 #include "base/supports_user_data.h"
 #include "ios/chrome/browser/application_context.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state_manager.h"
 #import "ios/chrome/browser/tabs/tab_model.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
@@ skipping 28 matching lines @@
   DCHECK_EQ([tab_models_ count], 0u);
 }
 
 // static
 TabModelList* TabModelList::GetForBrowserState(
     ios::ChromeBrowserState* browser_state,
     bool create) {
   TabModelList* tab_model_list =
       static_cast<TabModelList*>(browser_state->GetUserData(&kTabModelListKey));
   if (!tab_model_list && create) {
-    // The ownership of TabModelList is transfered to base::SupportsUserData
-    // via the SetUserData call (should take a std::unique_ptr<>).
     tab_model_list = new TabModelList;
-    browser_state->SetUserData(&kTabModelListKey, tab_model_list);
+    browser_state->SetUserData(&kTabModelListKey,
+                               base::WrapUnique(tab_model_list));
   }
   return tab_model_list;
 }
 }  // namespace
 
 void RegisterTabModelWithChromeBrowserState(
     ios::ChromeBrowserState* browser_state,
     TabModel* tab_model) {
   NSMutableSet<TabModel*>* tab_models =
       TabModelList::GetForBrowserState(browser_state, true)->tab_models();
@@ skipping 51 matching lines @@
       continue;
 
     for (TabModel* tab_model in tab_model_list->tab_models()) {
       if (![tab_model isEmpty])
         return true;
     }
   }
 
   return false;
 }