Refactor PrefHashStore's BeginTransaction to take a rawptr

components/user_prefs/tracked/tracked_preferences_migration_unittest.cc

 // Copyright 2014 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.
 
 #include "components/user_prefs/tracked/tracked_preferences_migration.h"
 
 #include <memory>
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 144 matching lines @@
         pref_hash_store.reset(new PrefHashStoreImpl(kSeed, kDeviceId, false));
         break;
       case MOCK_PROTECTED_PREF_STORE:
         store = protected_prefs_.get();
         pref_hash_store.reset(new PrefHashStoreImpl(kSeed, kDeviceId, true));
         break;
     }
     DCHECK(store);
 
     base::StringValue string_value(value);
-    pref_hash_store
-        ->BeginTransaction(std::unique_ptr<HashStoreContents>(
-            new DictionaryHashStoreContents(store)))
-        ->StoreHash(key, &string_value);
+    DictionaryHashStoreContents contents(store);
+    pref_hash_store->BeginTransaction(&contents)->StoreHash(key, &string_value);
   }
 
   // Returns true if the store opposite to |store_id| is observed for its next
   // successful write.
   bool WasOnSuccessfulWriteCallbackRegistered(MockPrefStoreID store_id) {
     switch (store_id) {
       case MOCK_UNPROTECTED_PREF_STORE:
         return !protected_store_successful_write_callback_.is_null();
       case MOCK_PROTECTED_PREF_STORE:
         return !unprotected_store_successful_write_callback_.is_null();
@@ skipping 467 matching lines @@
                        expected_unprotected_values);
 
     base::StringPairs expected_protected_values;
     expected_protected_values.push_back(std::make_pair(
         kProtectedPref, kProtectedPrefValue));
     expected_protected_values.push_back(std::make_pair(
         kPreviouslyUnprotectedPref, kPreviouslyUnprotectedPrefValue));
     VerifyValuesStored(MOCK_PROTECTED_PREF_STORE, expected_protected_values);
   }
 }