Revert of Rename RTPVideoHeader.isFirstPacket to .is_first_packet_in_frame.

webrtc/modules/rtp_rtcp/source/rtp_format_vp8.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 664 matching lines @@
     return false;
   }
 
   // Parse mandatory first byte of payload descriptor.
   bool extension = (*payload_data & 0x80) ? true : false;               // X bit
   bool beginning_of_partition = (*payload_data & 0x10) ? true : false;  // S bit
   int partition_id = (*payload_data & 0x0F);  // PartID field
 
   parsed_payload->type.Video.width = 0;
   parsed_payload->type.Video.height = 0;
-  parsed_payload->type.Video.is_first_packet_in_frame =
+  parsed_payload->type.Video.isFirstPacket =
       beginning_of_partition && (partition_id == 0);
   parsed_payload->type.Video.simulcastIdx = 0;
   parsed_payload->type.Video.codec = kRtpVideoVp8;
   parsed_payload->type.Video.codecHeader.VP8.nonReference =
       (*payload_data & 0x20) ? true : false;  // N bit
   parsed_payload->type.Video.codecHeader.VP8.partitionId = partition_id;
   parsed_payload->type.Video.codecHeader.VP8.beginningOfPartition =
       beginning_of_partition;
   parsed_payload->type.Video.codecHeader.VP8.pictureId = kNoPictureId;
   parsed_payload->type.Video.codecHeader.VP8.tl0PicIdx = kNoTl0PicIdx;
@@ skipping 40 matching lines @@
   if (ParseVP8FrameSize(parsed_payload, payload_data, payload_data_length) !=
       0) {
     return false;
   }
 
   parsed_payload->payload = payload_data;
   parsed_payload->payload_length = payload_data_length;
   return true;
 }
 }  // namespace webrtc