This can ... be a real problem for developers if we don't use the same info as ffmpeg.

The saved result differs slightly due to intentional bucketing. But we should be definitely bucketing the queried values in the same fashion. 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9e669479fcec5e72c7534b204cb60893b12895f1

commit 9e669479fcec5e72c7534b204cb60893b12895f1
Author: Chris Cunningham <chcunningham@chromium.org>
Date: Wed Nov 15 21:03:11 2017

Always bucket video metadata for DB I/O. Establish //media/capabilities.

This fixes a bug where we were not properly bucketing on the query-side.
We now bucket for all reads and writes.

Bucketting is enforced by the creation of a "bucketted"
VideoDecodeStatsDB::VideoDescKey. The key constructor is now private, so
all keys must be created via the bucketting path.

Bucketing also occurs in the VideoDecodeStatsReporter. This is mostly to
ensure that we don't start new stats records for slight changes to metadata
that wouldn't otherwise cause stats to be written to a new bucket.

Bug:  782707 
Change-Id: Ib8c1ded93ec8fe31014d74e45963863ebdb45788
Reviewed-on: https://chromium-review.googlesource.com/764572
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516822}
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/content/browser/browser_context.cc
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/BUILD.gn
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/blink/video_decode_stats_reporter.cc
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/blink/video_decode_stats_reporter.h
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/blink/video_decode_stats_reporter_unittest.cc
[add] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/BUILD.gn
[rename] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/DEPS
[add] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/bucket_utility.cc
[add] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/bucket_utility.h
[rename] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/video_decode_stats.proto
[rename] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/video_decode_stats_db.cc
[rename] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/video_decode_stats_db.h
[rename] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/video_decode_stats_db_impl.cc
[rename] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/video_decode_stats_db_impl.h
[rename] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/capabilities/video_decode_stats_db_unittest.cc
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/media_options.gni
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/mojo/BUILD.gn
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/mojo/services/BUILD.gn
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/mojo/services/video_decode_perf_history.cc
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/mojo/services/video_decode_perf_history.h
[modify] https://crrev.com/9e669479fcec5e72c7534b204cb60893b12895f1/media/mojo/services/video_decode_perf_history_unittest.cc