Standardize usage of virtual/override/final in base/

base/deferred_sequenced_task_runner.h

 // Copyright (c) 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.
 
 #ifndef BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_
 #define BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_
 
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
 #include "base/tracked_objects.h"
 
 namespace base {
 
 // A DeferredSequencedTaskRunner is a subclass of SequencedTaskRunner that
 // queues up all requests until the first call to Start() is issued.
 class BASE_EXPORT DeferredSequencedTaskRunner : public SequencedTaskRunner {
  public:
   explicit DeferredSequencedTaskRunner(
       const scoped_refptr<SequencedTaskRunner>& target_runner);
 
   // TaskRunner implementation
-  virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
-                               const Closure& task,
-                               TimeDelta delay) override;
-  virtual bool RunsTasksOnCurrentThread() const override;
+  bool PostDelayedTask(const tracked_objects::Location& from_here,
+                       const Closure& task,
+                       TimeDelta delay) override;
+  bool RunsTasksOnCurrentThread() const override;
 
   // SequencedTaskRunner implementation
-  virtual bool PostNonNestableDelayedTask(
-      const tracked_objects::Location& from_here,
-      const Closure& task,
-      TimeDelta delay) override;
+  bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
+                                  const Closure& task,
+                                  TimeDelta delay) override;
 
   // Start the execution - posts all queued tasks to the target executor. The
   // deferred tasks are posted with their initial delay, meaning that the task
   // execution delay is actually measured from Start.
   // Fails when called a second time.
   void Start();
 
  private:
   struct DeferredTask  {
     DeferredTask();
     ~DeferredTask();
 
     tracked_objects::Location posted_from;
     Closure task;
     // The delay this task was initially posted with.
     TimeDelta delay;
     bool is_non_nestable;
   };
 
-  virtual ~DeferredSequencedTaskRunner();
+  ~DeferredSequencedTaskRunner() override;
 
   // Creates a |Task| object and adds it to |deferred_tasks_queue_|.
   void QueueDeferredTask(const tracked_objects::Location& from_here,
                          const Closure& task,
                          TimeDelta delay,
                          bool is_non_nestable);
 
   // // Protects |started_| and |deferred_tasks_queue_|.
   mutable Lock lock_;
 
   bool started_;
   const scoped_refptr<SequencedTaskRunner> target_task_runner_;
   std::vector<DeferredTask> deferred_tasks_queue_;
 
   DISALLOW_COPY_AND_ASSIGN(DeferredSequencedTaskRunner);
 };
 
 }  // namespace base
 
 #endif  // BASE_DEFERRED_SEQUENCED_TASKRUNNER_H_