Standardize usage of virtual/override/final specifiers in device/.

device/hid/hid_connection_linux.cc

 // Copyright (c) 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 "device/hid/hid_connection_linux.h"
 
 #include <errno.h>
 #include <linux/hidraw.h>
 #include <sys/ioctl.h>
 
@@ skipping 25 matching lines @@
          base::WeakPtr<HidConnectionLinux> connection,
          scoped_refptr<base::SingleThreadTaskRunner> task_runner)
       : platform_file_(platform_file),
         connection_(connection),
         task_runner_(task_runner) {
     // Report buffers must always have room for the report ID.
     report_buffer_size_ = device_info.max_input_report_size + 1;
     has_report_id_ = device_info.has_report_id;
   }
 
-  virtual ~Helper() { DCHECK(thread_checker_.CalledOnValidThread()); }
+  ~Helper() override { DCHECK(thread_checker_.CalledOnValidThread()); }
 
   // Starts the FileDescriptorWatcher that reads input events from the device.
   // Must be called on a thread that has a base::MessageLoopForIO. The helper
   // object is owned by the thread where it was started.
   void Start() {
     base::ThreadRestrictions::AssertIOAllowed();
     thread_checker_.DetachFromThread();
     if (!base::MessageLoopForIO::current()->WatchFileDescriptor(
             platform_file_, true, base::MessageLoopForIO::WATCH_READ,
             &file_watcher_, this)) {
@@ skipping 240 matching lines @@
     PendingHidReport report = pending_reports_.front();
 
     pending_reports_.pop();
     if (CompleteRead(report.buffer, report.size, read.callback)) {
       pending_reads_.pop();
     }
   }
 }
 
 }  // namespace device