Mojo: Convert OVERRIDE -> override in mojo/{embedder,system}.

mojo/system/simple_dispatcher.h

 // 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.
 
 #ifndef MOJO_SYSTEM_SIMPLE_DISPATCHER_H_
 #define MOJO_SYSTEM_SIMPLE_DISPATCHER_H_
 
 #include <list>
 
 #include "base/macros.h"
@@ skipping 12 matching lines @@
  protected:
   SimpleDispatcher();
   virtual ~SimpleDispatcher();
 
   // To be called by subclasses when the state changes (so
   // |GetHandleSignalsStateImplNoLock()| should be checked again). Must be
   // called under lock.
   void HandleSignalsStateChangedNoLock();
 
   // |Dispatcher| protected methods:
-  virtual void CancelAllWaitersNoLock() OVERRIDE;
+  virtual void CancelAllWaitersNoLock() override;
   virtual MojoResult AddWaiterImplNoLock(
       Waiter* waiter,
       MojoHandleSignals signals,
       uint32_t context,
-      HandleSignalsState* signals_state) OVERRIDE;
+      HandleSignalsState* signals_state) override;
   virtual void RemoveWaiterImplNoLock(
       Waiter* waiter,
-      HandleSignalsState* signals_state) OVERRIDE;
+      HandleSignalsState* signals_state) override;
 
  private:
   // Protected by |lock()|:
   WaiterList waiter_list_;
 
   DISALLOW_COPY_AND_ASSIGN(SimpleDispatcher);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_SIMPLE_DISPATCHER_H_