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

base/memory/discardable_memory_mac.cc

Index: base/memory/discardable_memory_mac.cc
diff --git a/base/memory/discardable_memory_mac.cc b/base/memory/discardable_memory_mac.cc
index fa6a23145c389bbfe7d420c3a7a6f68b4ccfb8a8..57b9780914bd9070fae26bb1ba4e8429e697d671 100644
--- a/base/memory/discardable_memory_mac.cc
+++ b/base/memory/discardable_memory_mac.cc
@@ -56,7 +56,7 @@ class DiscardableMemoryMac
   }
 
   // Overridden from DiscardableMemory:
-  virtual DiscardableMemoryLockStatus Lock() OVERRIDE {
+  DiscardableMemoryLockStatus Lock() override {
     DCHECK(!is_locked_);
 
     bool purged = false;
@@ -68,19 +68,19 @@ class DiscardableMemoryMac
                   : DISCARDABLE_MEMORY_LOCK_STATUS_SUCCESS;
   }
 
-  virtual void Unlock() OVERRIDE {
+  void Unlock() override {
     DCHECK(is_locked_);
     g_shared_state.Pointer()->manager.ReleaseLock(this);
     is_locked_ = false;
   }
 
-  virtual void* Memory() const OVERRIDE {
+  void* Memory() const override {
     DCHECK(is_locked_);
     return reinterpret_cast<void*>(memory_.address());
   }
 
   // Overridden from internal::DiscardableMemoryManagerAllocation:
-  virtual bool AllocateAndAcquireLock() OVERRIDE {
+  bool AllocateAndAcquireLock() override {
     kern_return_t ret;
     bool persistent;
     if (!memory_.size()) {
@@ -123,7 +123,7 @@ class DiscardableMemoryMac
     return persistent;
   }
 
-  virtual void ReleaseLock() OVERRIDE {
+  void ReleaseLock() override {
     int state = VM_PURGABLE_VOLATILE | VM_VOLATILE_GROUP_DEFAULT;
     kern_return_t ret = vm_purgable_control(mach_task_self(),
                                             memory_.address(),
@@ -141,9 +141,7 @@ class DiscardableMemoryMac
 #endif
   }
 
-  virtual void Purge() OVERRIDE {
-    memory_.reset();
-  }
+  void Purge() override { memory_.reset(); }
 
  private:
   mac::ScopedMachVM memory_;