Introduce WebServiceWorkerNetworkProvider::GetProviderID() and stop static casting

Introduce WebServiceWorkerNetworkProvider::GetProviderID() and stop static casting

BUG=725090, 443374
Review-Url: https://codereview.chromium.org/2903523002
Cr-Commit-Position: refs/heads/master@{#473881}
Committed: https://chromium.googlesource.com/chromium/src/+/02fd70ff6d79411e5e5c503bd83a79453da76fb7

[horo, 2017-05-23 09:58:15]

The CQ bit was checked by horo@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-23 09:58:31]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[horo, 2017-05-23 11:27:29]

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

[horo, 2017-05-23 11:27:29]

kinuko@
Please review this.

[commit-bot: I haz the power, 2017-05-23 13:32:23]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-23 13:32:24]

Dry run: This issue passed the CQ dry run.

[kinuko, 2017-05-23 13:55:55]

Well, ok. lgtm

[horo, 2017-05-23 13:58:58]

The CQ bit was checked by horo@chromium.org

[commit-bot: I haz the power, 2017-05-23 13:59:14]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-23 14:02:46]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1495547938585900, "parent_rev":
"d094fefe4ebce2a81b28a9e0b1e7d2ed553a3b75", "commit_rev":
"02fd70ff6d79411e5e5c503bd83a79453da76fb7"}

[commit-bot: I haz the power, 2017-05-23 14:04:47]

Description was changed from

==========
Introduce WebServiceWorkerNetworkProvider::GetProviderID() and stop static
casting

BUG=725090,443374
==========

to

==========
Introduce WebServiceWorkerNetworkProvider::GetProviderID() and stop static
casting

BUG=725090,443374

Review-Url: https://codereview.chromium.org/2903523002
Cr-Commit-Position: refs/heads/master@{#473881}
Committed:
https://chromium.googlesource.com/chromium/src/+/02fd70ff6d79411e5e5c503bd83a...
==========

[commit-bot: I haz the power, 2017-05-23 14:04:48]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/02fd70ff6d79411e5e5c503bd83a...