Add tests for console messages of waitUntil() and respondWith()

Add tests for console messages of waitUntil() and respondWith()

This adds browser tests that verify console message logged when a
promise passed to waitUntil() or respondWith() is rejected.

These tests are here because console outputs from SWs aren't testable
with layout tests (crbug.com/456708).

BUG=359423
Committed: https://crrev.com/7f64887fa4067a08766179a313b623115b1e8f07
Cr-Commit-Position: refs/heads/master@{#325383}

[Kunihiko Sakamoto, 2015-04-15 09:30:38]

ksakamoto@chromium.org changed reviewers:
+ horo@chromium.org

[horo, 2015-04-16 01:43:28]

lgtm

[Kunihiko Sakamoto, 2015-04-16 01:51:38]

The CQ bit was checked by ksakamoto@chromium.org

[commit-bot: I haz the power, 2015-04-16 01:51:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1081953004/1

[commit-bot: I haz the power, 2015-04-16 02:53:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-16 02:54:51]

Patchset 1 (id:??) landed as
https://crrev.com/7f64887fa4067a08766179a313b623115b1e8f07
Cr-Commit-Position: refs/heads/master@{#325383}