Add DocWrite.Block metric for NavigationToFirstContentfulPaint.

Add DocWrite.Block metric for NavigationToFirstContentfulPaint.

We have ParseStartToFirstContentfulPaint for DocWrite.Block, which is
useful for understanding the exact impact of the change on the period
from parse start to FCP, but it's also important to measure the overall
time from navigation to FCP. This change adds a metric to track this
overall time.

BUG=626945
Committed: https://crrev.com/10ff30f72b8ac4d842ea154f29420a946a463b66
Cr-Commit-Position: refs/heads/master@{#404660}

[Bryan McQuade, 2016-07-11 12:43:58]

bmcquade@chromium.org changed reviewers:
+ shivanisha@chromium.org

[Bryan McQuade, 2016-07-11 12:43:58]

ptal

[shivanisha, 2016-07-11 15:06:38]

On 2016/07/11 at 12:43:58, bmcquade wrote:
> ptal

LGTM

[Bryan McQuade, 2016-07-11 15:13:19]

The CQ bit was checked by bmcquade@chromium.org

[commit-bot: I haz the power, 2016-07-11 15:13:28]

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, 2016-07-11 15:17:06]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-07-11 15:17:14]

CQ bit was unchecked.

[commit-bot: I haz the power, 2016-07-11 15:18:41]

Description was changed from

==========
Add DocWrite.Block metric for NavigationToFirstContentfulPaint.

We have ParseStartToFirstContentfulPaint for DocWrite.Block, which is
useful for understanding the exact impact of the change on the period
from parse start to FCP, but it's also important to measure the overall
time from navigation to FCP. This change adds a metric to track this
overall time.

BUG=626945
==========

to

==========
Add DocWrite.Block metric for NavigationToFirstContentfulPaint.

We have ParseStartToFirstContentfulPaint for DocWrite.Block, which is
useful for understanding the exact impact of the change on the period
from parse start to FCP, but it's also important to measure the overall
time from navigation to FCP. This change adds a metric to track this
overall time.

BUG=626945

Committed: https://crrev.com/10ff30f72b8ac4d842ea154f29420a946a463b66
Cr-Commit-Position: refs/heads/master@{#404660}
==========

[commit-bot: I haz the power, 2016-07-11 15:18:42]

Patchset 2 (id:??) landed as
https://crrev.com/10ff30f72b8ac4d842ea154f29420a946a463b66
Cr-Commit-Position: refs/heads/master@{#404660}