I have received info that this might actually be caused by a limitation in H264 parser that we have. I am going to test that theory first. We don't apparently support all nalu types and this might cause issues.

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/6bce6ad4859725cfcf274f48de3fcac13e886cca

commit 6bce6ad4859725cfcf274f48de3fcac13e886cca
Author: sakal <sakal@webrtc.org>
Date: Thu Mar 02 12:34:32 2017

H264BitstreamParser: Log nalu type when parsing slice type fails.

Decreases all parsing failures to a warning because they are not
critical errors. This is a speculative commit to help diagnose
why bots are failing.

BUG= chromium:697795 
TBR=stefan@webrtc.org

Review-Url: https://codereview.webrtc.org/2726833005
Cr-Commit-Position: refs/heads/master@{#16966}

[modify] https://crrev.com/6bce6ad4859725cfcf274f48de3fcac13e886cca/webrtc/common_video/h264/h264_bitstream_parser.cc

kthelgason promised to take a look if this is actually a problem in the parser

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/cabea3dbf25d23347539ce22803aa17f701e07f3

commit cabea3dbf25d23347539ce22803aa17f701e07f3
Author: sakal <sakal@webrtc.org>
Date: Thu Mar 02 14:55:07 2017

Revert of H264BitstreamParser: Log nalu type when parsing slice type fails. (patchset #1 id:60001 of https://codereview.webrtc.org/2726833005/ )

Reason for revert:
Investigation complete.

Original issue's description:
> H264BitstreamParser: Log nalu type when parsing slice type fails.
>
> Decreases all parsing failures to a warning because they are not
> critical errors. This is a speculative commit to help diagnose
> why bots are failing.
>
> BUG= chromium:697795 
> TBR=stefan@webrtc.org
>
> Review-Url: https://codereview.webrtc.org/2726833005
> Cr-Commit-Position: refs/heads/master@{#16966}
> Committed: https://chromium.googlesource.com/external/webrtc/+/6bce6ad4859725cfcf274f48de3fcac13e886cca

TBR=stefan@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= chromium:697795 

Review-Url: https://codereview.webrtc.org/2723883004
Cr-Commit-Position: refs/heads/master@{#16972}

[modify] https://crrev.com/cabea3dbf25d23347539ce22803aa17f701e07f3/webrtc/common_video/h264/h264_bitstream_parser.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/4c6df8893eb4aeea1fddb2b369bb9e4743a933f6

commit 4c6df8893eb4aeea1fddb2b369bb9e4743a933f6
Author: sakal <sakal@webrtc.org>
Date: Thu Mar 02 15:22:26 2017

Revert of Add QP for FFmpeg H264 decoder. (patchset #4 id:200001 of https://codereview.webrtc.org/2649133007/ )

Reason for revert:
Let's revert this while we investigate a problem in H264 bitstream parser.

Original issue's description:
> Add QP for FFmpeg H264 decoder.
>
> BUG= webrtc:6541 
>
> Review-Url: https://codereview.webrtc.org/2649133007
> Cr-Commit-Position: refs/heads/master@{#16942}
> Committed: https://chromium.googlesource.com/external/webrtc/+/879f4f6c3148fda61e988cd085e0520dc393a2af

TBR=sprang@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG= webrtc:6541 ,  chromium:697795 

Review-Url: https://codereview.webrtc.org/2726973003
Cr-Commit-Position: refs/heads/master@{#16974}

[modify] https://crrev.com/4c6df8893eb4aeea1fddb2b369bb9e4743a933f6/webrtc/modules/video_coding/BUILD.gn
[modify] https://crrev.com/4c6df8893eb4aeea1fddb2b369bb9e4743a933f6/webrtc/modules/video_coding/codecs/h264/h264_decoder_impl.cc
[modify] https://crrev.com/4c6df8893eb4aeea1fddb2b369bb9e4743a933f6/webrtc/modules/video_coding/codecs/h264/h264_decoder_impl.h
[delete] https://crrev.com/500f1b7a324c04d8920a32e29d01aaf87035034c/webrtc/modules/video_coding/codecs/h264/test/h264_impl_unittest.cc
[delete] https://crrev.com/500f1b7a324c04d8920a32e29d01aaf87035034c/webrtc/modules/video_coding/codecs/test/video_codec_test.cc
[delete] https://crrev.com/500f1b7a324c04d8920a32e29d01aaf87035034c/webrtc/modules/video_coding/codecs/test/video_codec_test.h
[modify] https://crrev.com/4c6df8893eb4aeea1fddb2b369bb9e4743a933f6/webrtc/modules/video_coding/codecs/vp9/test/vp9_impl_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/dea7f4f46f3d75eb01bad17537c3df2ce9ec4115

commit dea7f4f46f3d75eb01bad17537c3df2ce9ec4115
Author: kthelgason <kthelgason@webrtc.org>
Date: Mon Mar 06 10:49:36 2017

Ignore aud and sei NALus when parsing bitstream.

We currently don't know how to parse these NALus and we don't need
any information from them anyway so we might as well skip parsing them
and not break.

BUG= chromium:697795 

Review-Url: https://codereview.webrtc.org/2732623002
Cr-Commit-Position: refs/heads/master@{#17057}

[modify] https://crrev.com/dea7f4f46f3d75eb01bad17537c3df2ce9ec4115/webrtc/common_video/h264/h264_bitstream_parser.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/b8102e06347fbf3f19234c9e6449c8059b908e03

commit b8102e06347fbf3f19234c9e6449c8059b908e03
Author: sakal <sakal@webrtc.org>
Date: Mon Mar 06 11:52:55 2017

Reland of Add QP for FFmpeg H264 decoder. (patchset #1 id:1 of https://codereview.webrtc.org/2726973003/ )

Reason for revert:
The issue is now hopefully fixed.

Original issue's description:
> Revert of Add QP for FFmpeg H264 decoder. (patchset #4 id:200001 of https://codereview.webrtc.org/2649133007/ )
>
> Reason for revert:
> Let's revert this while we investigate a problem in H264 bitstream parser.
>
> Original issue's description:
> > Add QP for FFmpeg H264 decoder.
> >
> > BUG= webrtc:6541 
> >
> > Review-Url: https://codereview.webrtc.org/2649133007
> > Cr-Commit-Position: refs/heads/master@{#16942}
> > Committed: https://chromium.googlesource.com/external/webrtc/+/879f4f6c3148fda61e988cd085e0520dc393a2af
>
> TBR=sprang@webrtc.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG= webrtc:6541 ,  chromium:697795 
>
> Review-Url: https://codereview.webrtc.org/2726973003
> Cr-Commit-Position: refs/heads/master@{#16974}
> Committed: https://chromium.googlesource.com/external/webrtc/+/4c6df8893eb4aeea1fddb2b369bb9e4743a933f6

TBR=sprang@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG= webrtc:6541 ,  chromium:697795 

Review-Url: https://codereview.webrtc.org/2735733002
Cr-Commit-Position: refs/heads/master@{#17061}

[modify] https://crrev.com/b8102e06347fbf3f19234c9e6449c8059b908e03/webrtc/modules/video_coding/BUILD.gn
[modify] https://crrev.com/b8102e06347fbf3f19234c9e6449c8059b908e03/webrtc/modules/video_coding/codecs/h264/h264_decoder_impl.cc
[modify] https://crrev.com/b8102e06347fbf3f19234c9e6449c8059b908e03/webrtc/modules/video_coding/codecs/h264/h264_decoder_impl.h
[add] https://crrev.com/b8102e06347fbf3f19234c9e6449c8059b908e03/webrtc/modules/video_coding/codecs/h264/test/h264_impl_unittest.cc
[add] https://crrev.com/b8102e06347fbf3f19234c9e6449c8059b908e03/webrtc/modules/video_coding/codecs/test/video_codec_test.cc
[add] https://crrev.com/b8102e06347fbf3f19234c9e6449c8059b908e03/webrtc/modules/video_coding/codecs/test/video_codec_test.h
[modify] https://crrev.com/b8102e06347fbf3f19234c9e6449c8059b908e03/webrtc/modules/video_coding/codecs/vp9/test/vp9_impl_unittest.cc

The bots didn't fail on the reland.