Disable style sharing outside tests.

Disable style sharing outside tests.

This disables style sharing for most users in Canary, but leaves the code and
leaves it enabled in the layout tests. Once this bakes for a little while we
can then remove the code and update the tests.

Per the style-dev@ discussion and design doc:
https://groups.google.com/a/chromium.org/forum/#!topic/style-dev/8BV0QYubjos

[esprehn, 2017-05-05 05:10:53]

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

[commit-bot: I haz the power, 2017-05-05 05:11:12]

Dry run: CQ is trying da patch.

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

[esprehn, 2017-05-05 05:12:09]

Description was changed from

==========
Disable style sharing.

Per the style-dev@ discussion and design doc:
https://groups.google.com/a/chromium.org/forum/#!topic/style-dev/8BV0QYubjos
==========

to

==========
Disable style sharing outside tests.

This disables style sharing for most users in Canary, but leaves the code and
leaves it enabled in the layout tests. Once this bakes for a little while we
can then remove the code and update the tests.

Per the style-dev@ discussion and design doc:
https://groups.google.com/a/chromium.org/forum/#!topic/style-dev/8BV0QYubjos
==========

[commit-bot: I haz the power, 2017-05-05 07:01:40]

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

[commit-bot: I haz the power, 2017-05-05 07:01:40]

Dry run: Try jobs failed on following builders:
  linux_android_rel_ng on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[esprehn, 2017-05-05 19:12:17]

esprehn@chromium.org changed reviewers:
+ dtu@chromium.org, nainar@chromium.org, oysteine@chromium.org

[esprehn, 2017-05-05 19:12:18]

It seems some telemetry unit test is failing, and apparently only on android:
https://cs.chromium.org/chromium/src/tools/perf/measurements/blink_style_unit...

How do I debug this? The test fails on the line:

self.assertEquals(0, len(results.failures))

but doesn't print anything about what's inside .failures.

[nainar, 2017-05-08 01:29:55]

LGTM. 

No clue about the failing android telemetry test though. Tried grokking around
telemetry to see if I could see what failures could possibly be. Got nothing.
Would be interested in knowing what this is though.