Standardize usage of virtual/override/final in base/

base/threading/thread.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_THREADING_THREAD_H_
 #define BASE_THREADING_THREAD_H_
 
 #include <string>
 
 #include "base/base_export.h"
@@ skipping 54 matching lines @@
   explicit Thread(const std::string& name);
 
   // Destroys the thread, stopping it if necessary.
   //
   // NOTE: ALL SUBCLASSES OF Thread MUST CALL Stop() IN THEIR DESTRUCTORS (or
   // guarantee Stop() is explicitly called before the subclass is destroyed).
   // This is required to avoid a data race between the destructor modifying the
   // vtable, and the thread's ThreadMain calling the virtual method Run().  It
   // also ensures that the CleanUp() virtual method is called on the subclass
   // before it is destructed.
-  virtual ~Thread();
+  ~Thread() override;
 
 #if defined(OS_WIN)
   // Causes the thread to initialize COM.  This must be called before calling
   // Start() or StartWithOptions().  If |use_mta| is false, the thread is also
   // started with a TYPE_UI message loop.  It is an error to call
   // init_com_with_mta(false) and then StartWithOptions() with any message loop
   // type other than TYPE_UI.
   void init_com_with_mta(bool use_mta) {
     DCHECK(!started_);
     com_status_ = use_mta ? MTA : STA;
@@ skipping 108 matching lines @@
  private:
 #if defined(OS_WIN)
   enum ComStatus {
     NONE,
     STA,
     MTA,
   };
 #endif
 
   // PlatformThread::Delegate methods:
-  virtual void ThreadMain() override;
+  void ThreadMain() override;
 
 #if defined(OS_WIN)
   // Whether this thread needs to initialize COM, and if so, in what mode.
   ComStatus com_status_;
 #endif
 
   // Whether we successfully started the thread.
   bool started_;
 
   // If true, we're in the middle of stopping, and shouldn't access
@@ skipping 21 matching lines @@
   std::string name_;
 
   friend void ThreadQuitHelper();
 
   DISALLOW_COPY_AND_ASSIGN(Thread);
 };
 
 }  // namespace base
 
 #endif  // BASE_THREADING_THREAD_H_