Credential Management: Implement CredentialRequestOptions.

Credential Management: Implement CredentialRequestOptions.

As described in [1], the request method's signature now requires a
CredentialRequestOptions dictionary which wraps the various bits and
pieces that will be passed in in order to request credentials.

This patch puts those dictionaries in place, and wires them up to the
CredentialManagerClient.

[1]: https://w3c.github.io/webappsec/specs/credentialmanagement/#dictdef-credentialrequestoptions

BUG=494880
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197747

[Mike West, 2015-06-24 09:58:23]

mkwst@chromium.org changed reviewers:
+ jochen@chromium.org

[Mike West, 2015-06-24 09:58:24]

Mind taking a look?

-mike

[Mike West, 2015-06-24 11:57:08]

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

[commit-bot: I haz the power, 2015-06-24 11:57:17]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1205003002/1

[jochen (gone - plz use gerrit), 2015-06-24 14:56:00]

lgtm

[Mike West, 2015-06-24 15:34:58]

The CQ bit was unchecked by mkwst@chromium.org

[Mike West, 2015-06-24 15:35:00]

The CQ bit was checked by mkwst@chromium.org

[commit-bot: I haz the power, 2015-06-24 15:35:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1205003002/1

[commit-bot: I haz the power, 2015-06-24 15:40:01]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197747