Revert of Rename RTPVideoHeader.isFirstPacket to .is_first_packet_in_frame.

webrtc/modules/video_coding/video_packet_buffer_unittest.cc

Index: webrtc/modules/video_coding/video_packet_buffer_unittest.cc
diff --git a/webrtc/modules/video_coding/video_packet_buffer_unittest.cc b/webrtc/modules/video_coding/video_packet_buffer_unittest.cc
index 57f3ef84e700d2f274cf8341febadb84ac013a4b..1e2ef3ec2aca42965bd53b4f335c091b62f396ca 100644
--- a/webrtc/modules/video_coding/video_packet_buffer_unittest.cc
+++ b/webrtc/modules/video_coding/video_packet_buffer_unittest.cc
@@ -59,7 +59,7 @@
     packet.codec = kVideoCodecGeneric;
     packet.seqNum = seq_num;
     packet.frameType = keyframe ? kVideoFrameKey : kVideoFrameDelta;
-    packet.is_first_packet_in_frame = first == kFirst;
+    packet.isFirstPacket = first == kFirst;
     packet.markerBit = last == kLast;
     packet.sizeBytes = data_size;
     packet.dataPtr = data;
@@ -138,14 +138,14 @@
   packet.codec = kVideoCodecGeneric;
   packet.seqNum = seq_num;
   packet.frameType = kVideoFrameKey;
-  packet.is_first_packet_in_frame = true;
+  packet.isFirstPacket = true;
   packet.markerBit = false;
   packet.timesNacked = 0;
 
   packet_buffer_->InsertPacket(&packet);
 
   packet.seqNum++;
-  packet.is_first_packet_in_frame = false;
+  packet.isFirstPacket = false;
   packet.timesNacked = 1;
   packet_buffer_->InsertPacket(&packet);
 
@@ -363,7 +363,7 @@
   packet.video_header.codecHeader.H264.packetization_type = kH264SingleNalu;
   packet.dataPtr = data;
   packet.sizeBytes = sizeof(data_data);
-  packet.is_first_packet_in_frame = true;
+  packet.isFirstPacket = true;
   packet.markerBit = true;
   packet_buffer_->InsertPacket(&packet);