Delete VideoFrame default constructor, and IsZeroSize method.

webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.cc

 /*
  *  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 276 matching lines @@
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
 int32_t H264EncoderImpl::Encode(const VideoFrame& input_frame,
                                 const CodecSpecificInfo* codec_specific_info,
                                 const std::vector<FrameType>* frame_types) {
   if (!IsInitialized()) {
     ReportError();
     return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
   }
-  if (input_frame.IsZeroSize()) {
-    ReportError();
-    return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
-  }
   if (!encoded_image_callback_) {
     LOG(LS_WARNING) << "InitEncode() has been called, but a callback function "
                     << "has not been set with RegisterEncodeCompleteCallback()";
     ReportError();
     return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
   }
 
   bool force_key_frame = false;
   if (frame_types != nullptr) {
     // We only support a single stream.
@@ skipping 164 matching lines @@
 
 int32_t H264EncoderImpl::SetPeriodicKeyFrames(bool enable) {
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
 VideoEncoder::ScalingSettings H264EncoderImpl::GetScalingSettings() const {
   return VideoEncoder::ScalingSettings(true);
 }
 
 }  // namespace webrtc