Preparation CL for WebRTC performance test using promise-based getStats

Preparation CL for WebRTC performance test using promise-based getStats
Re-land of https://codereview.chromium.org/2534633002/

In order to have a perf test looking at stats of interest we need to be
able to get the results of a JavaScript getStats call. These can be
returned as JSON-stringified JavaScript dictionaries.

In this CL:
- [g|G]etStatsReportDictionary added to webrtc_browsertest_base.cc and
  peerconnection_getstats.js, which produce/read a JSON-stringified
  version of the stats.
- RTCStatsReportDictionary and RTCStatsDictionary, helper classes for
  reading stats from the base::Dictionary representation of the stats.
- Unittests for the helper classes.

In a follow-up CL these methods/classes will be used to obtain the
stats in the to-be-added performance test. This will yield pretty
graphs.

BUG=670306, 627816
Committed: https://crrev.com/4f0df039e3c3e854d5a527744e7855b09b4add67
Cr-Commit-Position: refs/heads/master@{#436252}

[hbos_chromium, 2016-12-02 11:00:55]

hbos@chromium.org changed reviewers:
+ hta@chromium.org, phoglund@chromium.org, tommi@chromium.org

[hbos_chromium, 2016-12-02 11:00:55]

Please take another look (reland), phoglund, hta and tommi

[hbos_chromium, 2016-12-02 11:01:05]

The CQ bit was checked by hbos@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-02 11:01:25]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-02 11:48:24]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-12-02 11:48:25]

Dry run: This issue passed the CQ dry run.

[tommi (sloooow) - chröme, 2016-12-02 13:18:45]

lgtm

https://codereview.chromium.org/2543173002/diff/20001/chrome/browser/media/we...
File chrome/browser/media/webrtc/test_stats_dictionary_unittest.cc (right):

https://codereview.chromium.org/2543173002/diff/20001/chrome/browser/media/we...
chrome/browser/media/webrtc/test_stats_dictionary_unittest.cc:22: const char
kTestStatsReportJson[] =
FYI - check out raw string literals - https://chromium-cpp.appspot.com/
Example use:
https://cs.chromium.org/chromium/src/tools/gn/command_ls.cc?rcl=0&l=21

[phoglund_chromium, 2016-12-02 15:50:03]

lgtm

[hta - Chromium, 2016-12-04 22:42:49]

lgtm

[hbos_chromium, 2016-12-05 09:06:41]

https://codereview.chromium.org/2543173002/diff/20001/chrome/browser/media/we...
File chrome/browser/media/webrtc/test_stats_dictionary_unittest.cc (right):

https://codereview.chromium.org/2543173002/diff/20001/chrome/browser/media/we...
chrome/browser/media/webrtc/test_stats_dictionary_unittest.cc:22: const char
kTestStatsReportJson[] =
On 2016/12/02 13:18:44, tommi (chrömium) wrote:
> FYI - check out raw string literals - https://chromium-cpp.appspot.com/
> Example use:
> https://cs.chromium.org/chromium/src/tools/gn/command_ls.cc?rcl=0&l=21

Oh! Done.

[hbos_chromium, 2016-12-05 09:07:09]

The CQ bit was checked by hbos@chromium.org

[hbos_chromium, 2016-12-05 09:07:10]

The patchset sent to the CQ was uploaded after l-g-t-m from
phoglund@chromium.org, hta@chromium.org, tommi@chromium.org
Link to the patchset: https://codereview.chromium.org/2543173002/#ps40001
(title: "Using raw string literals")

[commit-bot: I haz the power, 2016-12-05 09:07:27]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-05 10:11:39]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1480928829958730,
"parent_rev": "21919f2a7ccfa321b102acfafb4255e3da0f39af", "commit_rev":
"946b957a2e14acef5e2c54cf24af298e4fd06b4b"}

[commit-bot: I haz the power, 2016-12-05 10:12:15]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-12-05 10:13:50]

Description was changed from

==========
Preparation CL for WebRTC performance test using promise-based getStats
Re-land of https://codereview.chromium.org/2534633002/

In order to have a perf test looking at stats of interest we need to be
able to get the results of a JavaScript getStats call. These can be
returned as JSON-stringified JavaScript dictionaries.

In this CL:
- [g|G]etStatsReportDictionary added to webrtc_browsertest_base.cc and
  peerconnection_getstats.js, which produce/read a JSON-stringified
  version of the stats.
- RTCStatsReportDictionary and RTCStatsDictionary, helper classes for
  reading stats from the base::Dictionary representation of the stats.
- Unittests for the helper classes.

In a follow-up CL these methods/classes will be used to obtain the
stats in the to-be-added performance test. This will yield pretty
graphs.

BUG=670306, 627816
==========

to

==========
Preparation CL for WebRTC performance test using promise-based getStats
Re-land of https://codereview.chromium.org/2534633002/

In order to have a perf test looking at stats of interest we need to be
able to get the results of a JavaScript getStats call. These can be
returned as JSON-stringified JavaScript dictionaries.

In this CL:
- [g|G]etStatsReportDictionary added to webrtc_browsertest_base.cc and
  peerconnection_getstats.js, which produce/read a JSON-stringified
  version of the stats.
- RTCStatsReportDictionary and RTCStatsDictionary, helper classes for
  reading stats from the base::Dictionary representation of the stats.
- Unittests for the helper classes.

In a follow-up CL these methods/classes will be used to obtain the
stats in the to-be-added performance test. This will yield pretty
graphs.

BUG=670306, 627816

Committed: https://crrev.com/4f0df039e3c3e854d5a527744e7855b09b4add67
Cr-Commit-Position: refs/heads/master@{#436252}
==========

[commit-bot: I haz the power, 2016-12-05 10:13:51]

Patchset 3 (id:??) landed as
https://crrev.com/4f0df039e3c3e854d5a527744e7855b09b4add67
Cr-Commit-Position: refs/heads/master@{#436252}