Revert of Fix off-by-one bugs in video_coding::PacketBuffer when the buffer is filled with a single frame. (patchset #5 id:80001 of https://codereview.chromium.org/2993513002/ )

Reason for revert:
Break performance bots.

Original issue's description:
> Fix off-by-one bugs in video_coding::PacketBuffer when the buffer is filled with a single frame.
>
> BUG=webrtc:8028
>
> Review-Url: https://codereview.webrtc.org/2993513002
> Cr-Commit-Position: refs/heads/master@{#19209}
> Committed: https://chromium.googlesource.com/external/webrtc/+/ee13e8919c20de5860a510e91fac71fd5a7e9b8d

TBR=stefan@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:8028

Review-Url: https://codereview.webrtc.org/2990183002
Cr-Commit-Position: refs/heads/master@{#19211}
diff --git a/webrtc/modules/video_coding/frame_object.cc b/webrtc/modules/video_coding/frame_object.cc
index 663ea6f..4c4537c 100644
--- a/webrtc/modules/video_coding/frame_object.cc
+++ b/webrtc/modules/video_coding/frame_object.cc
@@ -93,7 +93,7 @@
     frame_type_ = first_packet->frameType;
   }
 
-  RTC_DCHECK(GetBitstream(_buffer));
+  GetBitstream(_buffer);
   _encodedWidth = first_packet->width;
   _encodedHeight = first_packet->height;