ExtensionsTest: Move initialization to SetUp and avoid potential UAF.

extensions/browser/lazy_background_task_queue_unittest.cc

 // Copyright 2013 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 "extensions/browser/lazy_background_task_queue.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/macros.h"
@@ skipping 96 matching lines @@
                                            .Build())
                     .Build())
             .SetID("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb")
             .Build();
     ExtensionRegistry::Get(browser_context())->AddEnabled(extension);
     return extension;
   }
 
  protected:
   void SetUp() override {
+    ExtensionsTest::SetUp();
     user_prefs::UserPrefs::Set(browser_context(), &testing_pref_service_);
   }
 
  private:
   sync_preferences::TestingPrefServiceSyncable testing_pref_service_;
 
   // The total number of pending tasks that have been executed.
   int task_run_count_;
 
   DISALLOW_COPY_AND_ASSIGN(LazyBackgroundTaskQueueTest);
@@ skipping 82 matching lines @@
   EXPECT_EQ(1u, queue.extensions_with_pending_tasks());
 
   // Processing tasks when there is one pending runs the task and removes the
   // extension from the list of extensions with pending tasks.
   queue.ProcessPendingTasks(NULL, browser_context(), extension.get());
   EXPECT_EQ(1, task_run_count());
   EXPECT_EQ(0u, queue.extensions_with_pending_tasks());
 }
 
 }  // namespace extensions