Revert of Add a flags field to video timing extension.

webrtc/sdk/objc/Framework/Classes/VideoToolbox/RTCVideoEncoderH264.mm

 /*
  *  Copyright (c) 2015 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 639 matching lines @@
   frame.buffer = [NSData dataWithBytesNoCopy:buffer->data() length:buffer->size() freeWhenDone:NO];
   frame.encodedWidth = width;
   frame.encodedHeight = height;
   frame.completeFrame = YES;
   frame.frameType = isKeyframe ? RTCFrameTypeVideoFrameKey : RTCFrameTypeVideoFrameDelta;
   frame.captureTimeMs = renderTimeMs;
   frame.timeStamp = timestamp;
   frame.rotation = rotation;
   frame.contentType = (_mode == RTCVideoCodecModeScreensharing) ? RTCVideoContentTypeScreenshare :
                                                                   RTCVideoContentTypeUnspecified;
-  frame.flags = webrtc::TimingFrameFlags::kInvalid;
+  frame.isTimingFrame = NO;
 
   int qp;
   _h264BitstreamParser.ParseBitstream(buffer->data(), buffer->size());
   _h264BitstreamParser.GetLastSliceQp(&qp);
   frame.qp = @(qp);
 
   BOOL res = _callback(frame, codecSpecificInfo, header);
   if (!res) {
     LOG(LS_ERROR) << "Encode callback failed";
     return;
   }
   _bitrateAdjuster->Update(frame.buffer.length);
 }
 
 - (RTCVideoEncoderQpThresholds *)scalingSettings {
   return [[RTCVideoEncoderQpThresholds alloc] initWithThresholdsLow:kLowH264QpThreshold
                                                                high:kHighH264QpThreshold];
 }
 
 @end