Use width,height for coded_{width,height} in AVStreamToVideoDecoderConfig

Anticipating AVStream.codec->coded_{width,height} will be inaccessible in
ffmpeg soon, this change uses just the width and height values as hints
of the coded size in AVStreamToVideoDecoderConfig (used only in
FFmpegDemuxerStream creation and tests). Once AVStream.codec becomes
deprecated, coded size fields are not externally populated unless we
spin up a temporary ffmpeg decoder to obtain that information.

It also drops the metadata logging in OnFindStreamInfoDone for
coded_size, since that metadata is no longer different than just width
and height, which are already logged.

Note that MSE MP4 parser has always just used the width, height for
coded size in similar construction of VideoDecoderConfigs in
MP4StreamParser.  MSE mp2t and WebM stream parsers appear to populate
coded size more precisely.

Marks VideoDecoderConfig.coded_size() and related histograms.xml
entries as deprecated.

BUG=591845, 665539
TEST=No media_unittests, ffmpeg_regression_tests regression under LSAN on linux

Review-Url: https://codereview.chromium.org/2506533002
Cr-Commit-Position: refs/heads/master@{#432300}
4 files changed