H264Decoder: Respect AUD, EOSeq and EOStream NAL units.
H264Decoder: Respect AUD, EOSeq and EOStream NAL units.

This is a reland of crrev.com/a07a9dca4dfc1b0e0263eef35b729278c9e5c5c0
by rafael.antognolli@intel.com, which seems to have been accidentally
lost during code reorganization.

TEST=vdatest,crosvideo.appspot.com
BUG=537574

Original commit message:

It's possible to finish a frame as soon as one of the above NAL units
are found in the data stream. This allows to display a frame sooner, without
the need to wait for the next frame NAL units.

Review URL: https://codereview.chromium.org/1407873005

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#358574}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk