Changed the css feature name trace string to avoid collisions

Changed the css feature name trace string to avoid collisions

We recently changed the feature-usage trace events to use the stable CSS
property ID.  This changes the label for the trace events so tools can
deterministically know that they are getting the new, stable property
ID's.

BUG=671731
Committed: https://crrev.com/941bbccd519d77ed2a7ce32be3860e6fc091dccd
Cr-Commit-Position: refs/heads/master@{#437042}

[Pat Meenan, 2016-12-07 16:23:19]

pmeenan@chromium.org changed reviewers:
+ rbyers@chromium.org

[Pat Meenan, 2016-12-07 16:23:19]

rbyers@ - Sorry I missed this in yesterday's CL.  I just realized that WPT could
pick up a mix of old and new ID's if we didn't also modify the label for the CSS
features.

[Rick Byers, 2016-12-07 16:50:37]

lgtm

[Pat Meenan, 2016-12-07 17:23:52]

The CQ bit was checked by pmeenan@chromium.org

[commit-bot: I haz the power, 2016-12-07 17:24:18]

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, 2016-12-07 20:05:27]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1481131432293250, "parent_rev":
"575dd77782f7c493d7a549e594df3e1113b55d11", "commit_rev":
"05bab5100b81814b4a0ceb83a9334ef0f3d61f71"}

[commit-bot: I haz the power, 2016-12-07 20:05:54]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-07 20:08:53]

Description was changed from

==========
Changed the css feature name trace string to avoid collisions

We recently changed the feature-usage trace events to use the stable CSS
property ID.  This changes the label for the trace events so tools can
deterministically know that they are getting the new, stable property
ID's.

BUG=671731
==========

to

==========
Changed the css feature name trace string to avoid collisions

We recently changed the feature-usage trace events to use the stable CSS
property ID.  This changes the label for the trace events so tools can
deterministically know that they are getting the new, stable property
ID's.

BUG=671731

Committed: https://crrev.com/941bbccd519d77ed2a7ce32be3860e6fc091dccd
Cr-Commit-Position: refs/heads/master@{#437042}
==========

[commit-bot: I haz the power, 2016-12-07 20:08:54]

Patchset 1 (id:??) landed as
https://crrev.com/941bbccd519d77ed2a7ce32be3860e6fc091dccd
Cr-Commit-Position: refs/heads/master@{#437042}