WebSocket header continuations test case.

WebSocket header continuations test case.

The old WebSocket implementation did not support header
continuations. The new implementation does. Add a regression test so
that we do not regress the fix accidentally.

TEST=net_unittests
BUG=169448
Committed: https://crrev.com/e1d6767039a418574cc1a8f9451c56538db096c5
Cr-Commit-Position: refs/heads/master@{#321326}

[Adam Rice, 2015-03-13 14:37:00]

ricea@chromium.org changed reviewers:
+ tyoshino@chromium.org

[Adam Rice, 2015-03-13 14:37:00]

No hurry.

[tyoshino (SeeGerritForStatus), 2015-03-19 03:34:54]

lgtm

[Adam Rice, 2015-03-19 07:50:08]

The CQ bit was checked by ricea@chromium.org

[Adam Rice, 2015-03-19 07:50:08]

The patchset sent to the CQ was uploaded after l-g-t-m from
tyoshino@chromium.org
Link to the patchset: https://codereview.chromium.org/1005113002/#ps20001
(title: "Rebase.")

[commit-bot: I haz the power, 2015-03-19 07:50:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1005113002/20001

[commit-bot: I haz the power, 2015-03-19 10:10:27]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-19 10:11:38]

Patchset 2 (id:??) landed as
https://crrev.com/e1d6767039a418574cc1a8f9451c56538db096c5
Cr-Commit-Position: refs/heads/master@{#321326}