Revert of Enable -Winconsistent-missing-override flag.

webrtc/modules/video_coding/jitter_buffer_unittest.cc

 /*
  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 197 matching lines @@
   }
 
   void RequestKeyFrame() override { ++keyframe_requests_; }
 
   ::testing::NiceMock<ProcessThreadMock> process_thread_mock_;
   std::vector<uint16_t> nack_sent_;
   int keyframe_requests_;
 
  protected:
   TestBasicJitterBuffer() : scoped_field_trial_(GetParam()) {}
-  void SetUp() override {
+  virtual void SetUp() {
     clock_.reset(new SimulatedClock(0));
     jitter_buffer_.reset(new VCMJitterBuffer(
         clock_.get(),
         std::unique_ptr<EventWrapper>(event_factory_.CreateEvent()),
         this,
         this));
     jitter_buffer_->Start();
     seq_num_ = 1234;
     timestamp_ = 0;
     size_ = 1400;
@@ skipping 2434 matching lines @@
 
   // Stream should be decodable from this point.
   clock_->AdvanceTimeMilliseconds(kDefaultFramePeriodMs);
   InsertFrame(kVideoFrameDelta);
   EXPECT_TRUE(DecodeCompleteFrame());
   nack_list = jitter_buffer_->GetNackList(&extended);
   EXPECT_EQ(0u, nack_list.size());
 }
 
 }  // namespace webrtc