Revert of Enable -Winconsistent-missing-override flag.

webrtc/modules/rtp_rtcp/source/receive_statistics_unittest.cc

 /*
  *  Copyright (c) 2013 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 139 matching lines @@
   EXPECT_EQ(2u, counters.transmitted.packets);
 }
 
 TEST_F(ReceiveStatisticsTest, RtcpCallbacks) {
   class TestCallback : public RtcpStatisticsCallback {
    public:
     TestCallback()
         : RtcpStatisticsCallback(), num_calls_(0), ssrc_(0), stats_() {}
     virtual ~TestCallback() {}
 
-    void StatisticsUpdated(const RtcpStatistics& statistics,
-                           uint32_t ssrc) override {
+    virtual void StatisticsUpdated(const RtcpStatistics& statistics,
+                                   uint32_t ssrc) {
       ssrc_ = ssrc;
       stats_ = statistics;
       ++num_calls_;
     }
 
     void CNameChanged(const char* cname, uint32_t ssrc) override {}
 
     uint32_t num_calls_;
     uint32_t ssrc_;
     RtcpStatistics stats_;
@@ skipping 201 matching lines @@
   callback.Matches(1, kSsrc1, expected);
 
   receive_statistics_->FecPacketReceived(header1_,
                                          kPacketSize1 + kHeaderLength);
   expected.fec.payload_bytes = kPacketSize1;
   expected.fec.header_bytes = kHeaderLength;
   expected.fec.packets = 1;
   callback.Matches(2, kSsrc1, expected);
 }
 }  // namespace webrtc