Remove SpdyStream::GetSSLCertRequestInfo.

Remove SpdyStream::GetSSLCertRequestInfo.

SPDY's multiplexing is incompatible with the renego + client auth hack. The old
implementation also assumed that the SpdyStream was still alive which isn't
true. We could attempt save a copy of it, but that doesn't resolve the
fundamental incompatibility of the hack. Instead
https://codereview.chromium.org/1131763002/ disables renegotiation, so this
codepath should be impossible.

BUG=462283
Committed: https://crrev.com/b38fe83bd9f34f101e705bff5397c9530b024edd
Cr-Commit-Position: refs/heads/master@{#329493}

[davidben, 2015-05-06 23:55:56]

davidben@chromium.org changed reviewers:
+ rch@chromium.org

[davidben, 2015-05-06 23:55:57]

This depends on the linked CL, otherwise the NOTREACHED is a lie.

[Ryan Hamilton, 2015-05-07 23:40:06]

AWESOME! LGTM

[davidben, 2015-05-12 20:58:15]

The CQ bit was checked by davidben@chromium.org

[commit-bot: I haz the power, 2015-05-12 20:58:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1128873008/1

[commit-bot: I haz the power, 2015-05-12 21:26:14]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-12 21:26:54]

Patchset 1 (id:??) landed as
https://crrev.com/b38fe83bd9f34f101e705bff5397c9530b024edd
Cr-Commit-Position: refs/heads/master@{#329493}