Delete IsZeroSize method.

webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_encoder.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 238 matching lines @@
   // TODO(tkchin): Try setting payload size via
   // kVTCompressionPropertyKey_MaxH264SliceBytes.
 
   return ResetCompressionSession();
 }
 
 int H264VideoToolboxEncoder::Encode(
     const VideoFrame& frame,
     const CodecSpecificInfo* codec_specific_info,
     const std::vector<FrameType>* frame_types) {
-  RTC_DCHECK(!frame.IsZeroSize());

[stefan-webrtc, 2016/09/05 14:45:25]

Could you comment on why this isn't necessary?

   if (!callback_ || !compression_session_) {
     return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
   }
 #if defined(WEBRTC_IOS)
   if (!RTCIsUIApplicationActive()) {
     // Ignore all encode requests when app isn't active. In this state, the
     // hardware encoder has been invalidated by the OS.
     return WEBRTC_VIDEO_CODEC_OK;
   }
 #endif
@@ skipping 357 matching lines @@
   if (result != 0) {
     LOG(LS_ERROR) << "Encode callback failed: " << result;
     return;
   }
   bitrate_adjuster_.Update(frame._size);
 }
 
 }  // namespace webrtc
 
 #endif  // defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)