Update from https://crrev.com/311076

base/mac/libdispatch_task_runner_unittest.cc

 // 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.
 
 #include "base/mac/libdispatch_task_runner.h"
 
 #include "base/bind.h"
 #include "base/mac/bind_objc_block.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class LibDispatchTaskRunnerTest : public testing::Test {
  public:
-  virtual void SetUp() override {
+  void SetUp() override {
     task_runner_ = new base::mac::LibDispatchTaskRunner(
         "org.chromium.LibDispatchTaskRunnerTest");
   }
 
   // DispatchLastTask is used to run the main test thread's MessageLoop until
   // all non-delayed tasks are run on the LibDispatchTaskRunner.
   void DispatchLastTask() {
     dispatch_async(task_runner_->GetDispatchQueue(), ^{
         message_loop_.PostTask(FROM_HERE,
                                base::MessageLoop::QuitWhenIdleClosure());
@@ skipping 189 matching lines @@
   })));
 
   const char* const expectations[] = {
     "BEGIN First",
     "END First",
     "BEGIN Second",
     "END Second"
   };
   VerifyTaskOrder(expectations, arraysize(expectations));
 }