replace 'virtual ... OVERRIDE' with '... override'

base/mac/libdispatch_task_runner.h

Index: base/mac/libdispatch_task_runner.h
diff --git a/base/mac/libdispatch_task_runner.h b/base/mac/libdispatch_task_runner.h
index b1d90e29acb191b054d54a690549c537d9988952..5377998295f4bd9ec0c33921c0fc65f3f34a595b 100644
--- a/base/mac/libdispatch_task_runner.h
+++ b/base/mac/libdispatch_task_runner.h
@@ -38,16 +38,15 @@ class BASE_EXPORT LibDispatchTaskRunner : public base::SingleThreadTaskRunner {
   explicit LibDispatchTaskRunner(const char* name);
 
   // base::TaskRunner:
-  virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
-                               const Closure& task,
-                               base::TimeDelta delay) OVERRIDE;
-  virtual bool RunsTasksOnCurrentThread() const OVERRIDE;
+  bool PostDelayedTask(const tracked_objects::Location& from_here,
+                       const Closure& task,
+                       base::TimeDelta delay) override;
+  bool RunsTasksOnCurrentThread() const override;
 
   // base::SequencedTaskRunner:
-  virtual bool PostNonNestableDelayedTask(
-      const tracked_objects::Location& from_here,
-      const Closure& task,
-      base::TimeDelta delay) OVERRIDE;
+  bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
+                                  const Closure& task,
+                                  base::TimeDelta delay) override;
 
   // This blocks the calling thread until all work on the dispatch queue has
   // been run and the queue has been destroyed. Destroying a queue requires