Update from chromium https://crrev.com/301725/

net/base/file_stream_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 "net/base/file_stream.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "base/files/file_util.h"
@@ skipping 28 matching lines @@
 IOBufferWithSize* CreateTestDataBuffer() {
   IOBufferWithSize* buf = new IOBufferWithSize(kTestDataSize);
   memcpy(buf->data(), kTestData, kTestDataSize);
   return buf;
 }
 
 }  // namespace
 
 class FileStreamTest : public PlatformTest {
  public:
-  virtual void SetUp() {
+  void SetUp() override {
     PlatformTest::SetUp();
 
     base::CreateTemporaryFile(&temp_file_path_);
     base::WriteFile(temp_file_path_, kTestData, kTestDataSize);
   }
-  virtual void TearDown() {
+  void TearDown() override {
     // FileStreamContexts must be asynchronously closed on the file task runner
     // before they can be deleted. Pump the RunLoop to avoid leaks.
     base::RunLoop().RunUntilIdle();
     EXPECT_TRUE(base::DeleteFile(temp_file_path_, false));
 
     PlatformTest::TearDown();
   }
 
   const base::FilePath temp_file_path() const { return temp_file_path_; }
 
@@ skipping 808 matching lines @@
     total_bytes_read += rv;
     data_read.append(buf->data(), rv);
   }
   EXPECT_EQ(file_size, total_bytes_read);
 }
 #endif
 
 }  // namespace
 
 }  // namespace net