Replace OVERRIDE->override and FINAL->final since we now require C++11.

src/base/platform/mutex.h

Index: src/base/platform/mutex.h
diff --git a/src/base/platform/mutex.h b/src/base/platform/mutex.h
index 5d0e57be57cb8141eee5fceaa37581b0679c6e46..18e85de7bcaf6cd45bd5e77ba1d4590055e832ef 100644
--- a/src/base/platform/mutex.h
+++ b/src/base/platform/mutex.h
@@ -33,7 +33,7 @@ namespace base {
 // |TryLock()|. The behavior of a program is undefined if a mutex is destroyed
 // while still owned by some thread. The Mutex class is non-copyable.
 
-class Mutex FINAL {
+class Mutex final {
  public:
   Mutex();
   ~Mutex();
@@ -127,7 +127,7 @@ typedef LazyStaticInstance<Mutex, DefaultConstructTrait<Mutex>,
 // The behavior of a program is undefined if a recursive mutex is destroyed
 // while still owned by some thread. The RecursiveMutex class is non-copyable.
 
-class RecursiveMutex FINAL {
+class RecursiveMutex final {
  public:
   RecursiveMutex();
   ~RecursiveMutex();
@@ -199,7 +199,7 @@ typedef LazyStaticInstance<RecursiveMutex,
 // The LockGuard class is non-copyable.
 
 template <typename Mutex>
-class LockGuard FINAL {
+class LockGuard final {
  public:
   explicit LockGuard(Mutex* mutex) : mutex_(mutex) { mutex_->Lock(); }
   ~LockGuard() { mutex_->Unlock(); }