Standardize usage of virtual/override/final specifiers.

chrome/browser/net/probe_message_unittest.cc

 // Copyright 2013 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 <string.h>
 
 #include "chrome/browser/net/probe_message.h"
 #include "chrome/browser/net/probe_message.pb.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace chrome_browser_net {
 
 class ProbeMessageTest : public ::testing::Test {
  protected:
   ProbeMessageTest() {}
 
-  virtual ~ProbeMessageTest() {}
+  ~ProbeMessageTest() override {}
 };
 
 TEST_F(ProbeMessageTest, TestGenerateProbeRequest) {
   ProbeMessage pm;
   ProbePacket_Token token;
   token.set_timestamp_micros(1000000U);
   token.mutable_hash()->assign("1x1x");
   uint32 group_id = 1;
   uint32 probe_size = 500;
   uint32 pacing_interval_micros = 1000000;
@@ skipping 69 matching lines @@
     expected_str[i] = original[i] ^ ProbeMessage::kEncodingString[i];
   }
   EXPECT_EQ(output, expected_str);
 
   // Do it again to decode.
   std::string twice_encoded = pm.Encode(output);
   EXPECT_EQ(twice_encoded, original);
 }
 
 }  // namespace chrome_browser_net