Add UMA histogram Blink.PrePaint.UpdateTime

Add UMA histogram Blink.PrePaint.UpdateTime

BUG=646176
Review-Url: https://codereview.chromium.org/2615713004
Cr-Commit-Position: refs/heads/master@{#441827}
Committed: https://chromium.googlesource.com/chromium/src/+/0955147b8de3c2dd81b68aedb92872aaf418fc2b

[Xianzhu, 2017-01-05 18:44:20]

wangxianzhu@chromium.org changed reviewers:
+ chrishtr@chromium.org, jochen@chromium.org, wkorman@chromium.org

[Xianzhu, 2017-01-05 18:46:20]

wangxianzhu@chromium.org changed reviewers:
+ holte@chromium.org
- jochen@chromium.org

[Xianzhu, 2017-01-05 18:46:20]

s/jochen/holte/ because jochen reviews UseCounter only.

[Steven Holte, 2017-01-05 21:55:51]

lgtm

[chrishtr, 2017-01-05 23:02:51]

lgtm

[Xianzhu, 2017-01-05 23:08:40]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2017-01-05 23:09:32]

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

[commit-bot: I haz the power, 2017-01-05 23:09:33]

This CL has an open dependency (Issue 2613983002 Patch 20001). Please resolve
the dependency and try again.
If you are sure that there is no real dependency, please use one of the options
listed in https://goo.gl/9Es4OR to land the CL.

[Xianzhu, 2017-01-05 23:35:00]

The CQ bit was checked by wangxianzhu@chromium.org

[Xianzhu, 2017-01-05 23:35:00]

The patchset sent to the CQ was uploaded after l-g-t-m from
chrishtr@chromium.org, holte@chromium.org
Link to the patchset: https://codereview.chromium.org/2615713004/#ps20001
(title: "Rebase on origin/master")

[commit-bot: I haz the power, 2017-01-05 23:35:59]

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, 2017-01-06 02:20:13]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1483659300425540,
"parent_rev": "30714627739ff4d08c1621702fa70fe396cbb89d", "commit_rev":
"0955147b8de3c2dd81b68aedb92872aaf418fc2b"}

[commit-bot: I haz the power, 2017-01-06 02:20:41]

Description was changed from

==========
Add UMA histogram Blink.PrePaint.UpdateTime

BUG=646176
==========

to

==========
Add UMA histogram Blink.PrePaint.UpdateTime

BUG=646176

Review-Url: https://codereview.chromium.org/2615713004
Cr-Commit-Position: refs/heads/master@{#441827}
Committed:
https://chromium.googlesource.com/chromium/src/+/0955147b8de3c2dd81b68aedb928...
==========

[commit-bot: I haz the power, 2017-01-06 02:20:42]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/0955147b8de3c2dd81b68aedb928...