[PushMessaging] Use appopriate type parameters for WebCallbacks (1/3).

[PushMessaging] Use appopriate type parameters for WebCallbacks (1/3).

This series of CLs fixes WebCallback parameter types used in PushMessaging.

 - WebPushSubscription* (ownership transferred)
  => PassOwnPtr<WebPushSubscription>
 - WebPushPermissionStatus* (ownership not transferred)
  => WebPushPermissionStatus
 - WebPushError* (ownership transferred)
  => const WebPushError&

1/3: https://codereview.chromium.org/1304723002/
2/3: https://codereview.chromium.org/1291023005/
3/3: https://codereview.chromium.org/1302833004/

BUG=493531
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=200923

[yhirano, 2015-08-20 06:19:16]

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

[Michael van Ouwerkerk, 2015-08-20 13:32:19]

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

[Michael van Ouwerkerk, 2015-08-20 13:32:20]

lgtm

[mlamouri (slow - plz ping), 2015-08-20 17:07:33]

The CQ bit was checked by mlamouri@chromium.org

[commit-bot: I haz the power, 2015-08-20 17:07:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1304723002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1304723002/20001

[commit-bot: I haz the power, 2015-08-20 19:15:50]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=200923