Update the Notification Blink API to use integral persistent ids.

Update the Notification Blink API to use integral persistent ids.

Chromium now maintains persistent notification ids as integers, so
Blink should be updated to match this.

This CL is part of a three-sided patch:
  [1] This CL.
  [2] https://codereview.chromium.org/1071203002/
  [3] https://codereview.chromium.org/1072873002/

BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=193707

[Peter Beverloo, 2015-04-09 16:18:40]

peter@chromium.org changed reviewers:
+ johnme@chromium.org, mkwst@chromium.org

[Peter Beverloo, 2015-04-09 16:18:40]

Three-sided patches to change the type of an argument are painful :-(.

The duplication is necessary in order to not break any pages, and is being
removed again in the third patch.

PTAL

[johnme, 2015-04-10 11:08:44]

notifications lgtm, modulo comment at
https://codereview.chromium.org/1072873002/diff/1/Source/modules/notification...

[Mike West, 2015-04-10 11:12:26]

LGTM.

[Peter Beverloo, 2015-04-14 12:48:25]

The CQ bit was checked by peter@chromium.org

[commit-bot: I haz the power, 2015-04-14 12:48:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1078783002/1

[commit-bot: I haz the power, 2015-04-14 15:02:29]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=193707