ServiceWorker cleanup: remove wait_for_update() in favor of r.installing in most tests

ServiceWorker cleanup: remove wait_for_update() in favor of r.installing in most tests

Unless we really want to wait for onupdate event we can simply use
registration.installing in most tests.

I left wait_for_update usage() in:
- register-same-scope-different-script-url.html
- registration-service-worker-attributes.html
- unregister-then-register-new-script.html
as they appeared that they explicitly want to wait for 'onupdate'.

BUG=439365
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=186697

[kinuko, 2014-12-05 07:53:58]

Patchset #1 (id:1) has been deleted

[kinuko, 2014-12-05 07:57:18]

kinuko@chromium.org changed reviewers:
+ falken@chromium.org

[kinuko, 2014-12-05 07:57:33]

kinuko@chromium.org changed reviewers:
+ nhiroki@chromium.org

[kinuko, 2014-12-05 07:58:45]

falken@ or nhiroki@: either one of you can review this? (Low priority cleanup
patch, based on falken's suggestion in
https://codereview.chromium.org/773153002/#msg4)

[falken, 2014-12-08 02:13:44]

lgtm, thanks

Now another cleanup task can be removing "wait_for_activated" or simply making
it a shortcut for "wait_for_state(r.installing, "activated")". As it is,
wait_for_activated tries to sweep race conditions under the rug that our tests
should fail on.

[kinuko, 2014-12-08 12:53:00]

The CQ bit was checked by kinuko@chromium.org

[commit-bot: I haz the power, 2014-12-08 12:53:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/776373003/20001

[commit-bot: I haz the power, 2014-12-08 12:56:44]

Committed patchset #1 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=186697