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

base/threading/simple_thread.h

Index: base/threading/simple_thread.h
diff --git a/base/threading/simple_thread.h b/base/threading/simple_thread.h
index df03ce1c8131e32144003989acb0eb4e5732381e..7362d1c4b88dfdf1deb5e56e87c74c516e676c6c 100644
--- a/base/threading/simple_thread.h
+++ b/base/threading/simple_thread.h
@@ -102,7 +102,7 @@ class BASE_EXPORT SimpleThread : public PlatformThread::Delegate {
   bool HasBeenJoined() { return joined_; }
 
   // Overridden from PlatformThread::Delegate:
-  virtual void ThreadMain() OVERRIDE;
+  void ThreadMain() override;
 
   // Only set priorities with a careful understanding of the consequences.
   // This is meant for very limited use cases.
@@ -136,7 +136,8 @@ class BASE_EXPORT DelegateSimpleThread : public SimpleThread {
                        const Options& options);
 
   virtual ~DelegateSimpleThread();
-  virtual void Run() OVERRIDE;
+  void Run() override;
+
  private:
   Delegate* delegate_;
 };
@@ -174,7 +175,7 @@ class BASE_EXPORT DelegateSimpleThreadPool
   }
 
   // We implement the Delegate interface, for running our internal threads.
-  virtual void Run() OVERRIDE;
+  void Run() override;
 
  private:
   const std::string name_prefix_;