Some more virtual/override updates.

mojo/public/cpp/bindings/tests/handle_passing_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 "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/test_support/test_utils.h"
 #include "mojo/public/cpp/utility/run_loop.h"
 #include "mojo/public/interfaces/bindings/tests/sample_factory.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 148 matching lines @@
 
  private:
   ScopedMessagePipeHandle pipe1_;
   ScopedMessagePipeHandle pipe3_;
   std::string expected_text_reply_;
   bool got_response_;
 };
 
 class HandlePassingTest : public testing::Test {
  public:
-  virtual void TearDown() { PumpMessages(); }
+  void TearDown() override { PumpMessages(); }
 
   void PumpMessages() { loop_.RunUntilIdle(); }
 
  private:
   Environment env_;
   RunLoop loop_;
 };
 
 TEST_F(HandlePassingTest, Basic) {
   sample::FactoryPtr factory;
@@ skipping 153 matching lines @@
 
   PumpMessages();  // Yield for results.
 
   EXPECT_EQ(std::string("object1"), name1);
   EXPECT_EQ(std::string("object2"), name2);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo