Revert of Rename RTPVideoHeader.isFirstPacket to .is_first_packet_in_frame.

webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc

Index: webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc b/webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
index 9c4dcd9fa7b12eaa45a1b95c8780b3d2d209cc83..e896c65f97269db765d112ce6965b903f4d378bd 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
@@ -389,7 +389,7 @@
   parsed_payload->type.Video.width = 0;
   parsed_payload->type.Video.height = 0;
   parsed_payload->type.Video.codec = kRtpVideoH264;
-  parsed_payload->type.Video.is_first_packet_in_frame = true;
+  parsed_payload->type.Video.isFirstPacket = true;
   RTPVideoHeaderH264* h264_header =
       &parsed_payload->type.Video.codecHeader.H264;
 
@@ -610,7 +610,7 @@
   parsed_payload->type.Video.width = 0;
   parsed_payload->type.Video.height = 0;
   parsed_payload->type.Video.codec = kRtpVideoH264;
-  parsed_payload->type.Video.is_first_packet_in_frame = first_fragment;
+  parsed_payload->type.Video.isFirstPacket = first_fragment;
   RTPVideoHeaderH264* h264 = &parsed_payload->type.Video.codecHeader.H264;
   h264->packetization_type = kH264FuA;
   h264->nalu_type = original_nal_type;