Clean up deprecated Web Push API code-paths.

Clean up deprecated Web Push API code-paths.

Remove the Blink API implementations which still accepted a WebString
for the sender Id, which is not being used anymore.

BUG=424601
Committed: https://crrev.com/28298bf4c9cf9f88660bd73f4576e3f41eac3470
Cr-Commit-Position: refs/heads/master@{#301348}

[Peter Beverloo, 2014-10-17 14:48:37]

peter@chromium.org changed reviewers:
+ mvanouwerkerk@chromium.org

[Peter Beverloo, 2014-10-17 14:48:38]

PTAL. This depends on https://codereview.chromium.org/661093002/ and it rolling
into Chromium.

[Michael van Ouwerkerk, 2014-10-21 12:51:43]

lgtm

[Peter Beverloo, 2014-10-24 15:47:04]

peter@chromium.org changed reviewers:
+ sievers@chromium.org

[Peter Beverloo, 2014-10-24 15:47:04]

+sievers for //content stamp.

This is the last part of a simple 3-patch cleanup.
  (1) https://codereview.chromium.org/640593003/
  (2) https://codereview.chromium.org/661093002/ [blink]
  (3) [this]

[no sievers, 2014-10-24 17:57:48]

lgtm

[Peter Beverloo, 2014-10-27 11:35:22]

Blink-side was rolled into Chromium yesterday:
  https://chromium.googlesource.com/chromium/blink/+log/3e1901b..ff95c8e

So putting this on the queue. Thanks for the reviews all!

[Peter Beverloo, 2014-10-27 11:35:26]

The CQ bit was checked by peter@chromium.org

[commit-bot: I haz the power, 2014-10-27 11:36:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/663813002/20001

[commit-bot: I haz the power, 2014-10-27 12:32:55]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-10-27 12:33:27]

Patchset 2 (id:??) landed as
https://crrev.com/28298bf4c9cf9f88660bd73f4576e3f41eac3470
Cr-Commit-Position: refs/heads/master@{#301348}