Standardize usage of virtual/override/final in base/

base/files/file_path_watcher_fsevents.cc

 // Copyright 2014 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.
 
 #include "base/files/file_path_watcher_fsevents.h"
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
@@ skipping 10 matching lines @@
 // The latency parameter passed to FSEventsStreamCreate().
 const CFAbsoluteTime kEventLatencySeconds = 0.3;
 
 class FSEventsTaskRunner : public mac::LibDispatchTaskRunner {
  public:
    FSEventsTaskRunner()
        : mac::LibDispatchTaskRunner("org.chromium.FilePathWatcherFSEvents") {
    }
 
  protected:
-   virtual ~FSEventsTaskRunner() {}
+  ~FSEventsTaskRunner() override {}
 };
 
 static LazyInstance<FSEventsTaskRunner>::Leaky g_task_runner =
     LAZY_INSTANCE_INITIALIZER;
 
 // Resolve any symlinks in the path.
 FilePath ResolvePath(const FilePath& path) {
   const unsigned kMaxLinksToResolve = 255;
 
   std::vector<FilePath::StringType> component_vector;
@@ skipping 212 matching lines @@
 void FilePathWatcherFSEvents::StartEventStream(
     FSEventStreamEventId start_event) {
   DCHECK(g_task_runner.Get().RunsTasksOnCurrentThread());
   ResolveTargetPath();
   UpdateEventStream(start_event);
 }
 
 FilePathWatcherFSEvents::~FilePathWatcherFSEvents() {}
 
 }  // namespace base