Fix bug in service worker push tests: don't cache subscription options

Fix bug in service worker push tests: don't cache subscription options

- This bug meant that calling workerSubscribeNoKey after workerSubscribe
would actually subscribe with the cached key instead of no key.
- This meant that some tests in PushMessagingBrowserTest were not
testing exactly what they intended to test, prior to this patch.

BUG=

Review-Url: https://codereview.chromium.org/2449963002
Cr-Commit-Position: refs/heads/master@{#428108}
(cherry picked from commit db15f2e4e890234356aaa82befafb0efb917cd20)

Merge approval: https://crbug.com/659230#c25

Committed: https://chromium.googlesource.com/chromium/src/+/d49d16d7d503c10d4bb12de178bc54d6af1efdce

[johnme, 2016-11-21 13:56:29]

Description was changed from

==========
Fix bug in service worker push tests: don't cache subscription options

- This bug meant that calling workerSubscribeNoKey after workerSubscribe
would actually subscribe with the cached key instead of no key.
- This meant that some tests in PushMessagingBrowserTest were not
testing exactly what they intended to test, prior to this patch.

BUG=

Review-Url: https://codereview.chromium.org/2449963002
Cr-Commit-Position: refs/heads/master@{#428108}
(cherry picked from commit db15f2e4e890234356aaa82befafb0efb917cd20)

Merge approval: https://crbug.com/659230#c25
==========

to

==========
Fix bug in service worker push tests: don't cache subscription options

- This bug meant that calling workerSubscribeNoKey after workerSubscribe
would actually subscribe with the cached key instead of no key.
- This meant that some tests in PushMessagingBrowserTest were not
testing exactly what they intended to test, prior to this patch.

BUG=

Review-Url: https://codereview.chromium.org/2449963002
Cr-Commit-Position: refs/heads/master@{#428108}
(cherry picked from commit db15f2e4e890234356aaa82befafb0efb917cd20)

Merge approval: https://crbug.com/659230#c25

Committed:
https://chromium.googlesource.com/chromium/src/+/d49d16d7d503c10d4bb12de178bc...
==========

[johnme, 2016-11-21 13:56:30]

Committed patchset #1 (id:1) manually as
d49d16d7d503c10d4bb12de178bc54d6af1efdce.