[Extensions] Add metrics for execution time of binding.js

[Extensions] Add metrics for execution time of binding.js

Add UMA for the time it takes for the BindingGeneratingNativeHandler
to create the JS object representing an API object. Since this tends to
be a fast process (but a repeated one), use microsecond accuracy.

BUG=608561
Committed: https://crrev.com/c6be58d620359b6c02b4b8b60a554dff2a928e6e
Cr-Commit-Position: refs/heads/master@{#423384}

[Devlin, 2016-10-05 21:24:02]

rdevlin.cronin@chromium.org changed reviewers:
+ lazyboy@chromium.org, mpearson@chromium.org

[Devlin, 2016-10-05 21:24:02]

Mark and lazyboy@, mind taking a look?

[Mark P, 2016-10-05 23:02:45]

lgtm

[lazyboy, 2016-10-05 23:33:29]

lgtm.

[Devlin, 2016-10-06 00:16:36]

The CQ bit was checked by rdevlin.cronin@chromium.org

[commit-bot: I haz the power, 2016-10-06 00:17:37]

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, 2016-10-06 01:36:19]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-06 01:38:54]

Description was changed from

==========
[Extensions] Add metrics for execution time of binding.js

Add UMA for the time it takes for the BindingGeneratingNativeHandler
to create the JS object representing an API object. Since this tends to
be a fast process (but a repeated one), use microsecond accuracy.

BUG=608561
==========

to

==========
[Extensions] Add metrics for execution time of binding.js

Add UMA for the time it takes for the BindingGeneratingNativeHandler
to create the JS object representing an API object. Since this tends to
be a fast process (but a repeated one), use microsecond accuracy.

BUG=608561

Committed: https://crrev.com/c6be58d620359b6c02b4b8b60a554dff2a928e6e
Cr-Commit-Position: refs/heads/master@{#423384}
==========

[commit-bot: I haz the power, 2016-10-06 01:38:55]

Patchset 1 (id:??) landed as
https://crrev.com/c6be58d620359b6c02b4b8b60a554dff2a928e6e
Cr-Commit-Position: refs/heads/master@{#423384}