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

base/compiler_specific.h

 // Copyright (c) 2012 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_COMPILER_SPECIFIC_H_
 #define BASE_COMPILER_SPECIFIC_H_
 
 #include "build/build_config.h"
 
 #if defined(COMPILER_MSVC)
@@ skipping 118 matching lines @@
 //   ALIGNOF(int32)  // this would be 4
 #if defined(COMPILER_MSVC)
 #define ALIGNOF(type) (sizeof(type) - sizeof(type) + __alignof(type))
 #elif defined(COMPILER_GCC)
 #define ALIGNOF(type) __alignof__(type)
 #endif
 
 // Annotate a virtual method indicating it must be overriding a virtual
 // method in the parent class.
 // Use like:
-//   virtual void foo() OVERRIDE;
+//   void foo() override;
 #define OVERRIDE override
 
 // Annotate a virtual method indicating that subclasses must not override it,
 // or annotate a class to indicate that it cannot be subclassed.
 // Use like:
 //   virtual void foo() FINAL;
 //   class B FINAL : public A {};
 #define FINAL final
 
 // Annotate a function indicating the caller must examine the return value.
@@ skipping 49 matching lines @@
 // Macro for hinting that an expression is likely to be false.
 #if !defined(UNLIKELY)
 #if defined(COMPILER_GCC)
 #define UNLIKELY(x) __builtin_expect(!!(x), 0)
 #else
 #define UNLIKELY(x) (x)
 #endif  // defined(COMPILER_GCC)
 #endif  // !defined(UNLIKELY)
 
 #endif  // BASE_COMPILER_SPECIFIC_H_