ProxyScriptDecider: Fix NOTREACHED in Cancel()

ProxyScriptDecider: Fix NOTREACHED in Cancel()

Cancel() has an overly paranoid NOTREACHED, which makes it unsafe to cancel a
ProxyScriptDecider in between quickcheck and proxy script fetching. This CL
removes that NOTREACHED altogether, and adds a test to cover it.

BUG=409698
Committed: https://crrev.com/d83ea6db85677c1732c230d40b2af9b3da433228
Cr-Commit-Position: refs/heads/master@{#318739}

[Elly Fong-Jones, 2015-02-27 21:50:25]

ellyjones@chromium.org changed reviewers:
+ mmenke@chromium.org

[Elly Fong-Jones, 2015-02-27 21:50:34]

ptal? :)

[Elly Fong-Jones, 2015-02-27 21:54:32]

ellyjones@chromium.org changed reviewers:
+ eroman@chromium.org
- mmenke@chromium.org

[Elly Fong-Jones, 2015-02-27 21:54:43]

er, this time with r=eroman, PTAL? :)

[eroman, 2015-02-27 22:00:26]

lgtm

[Elly Fong-Jones, 2015-03-02 18:46:59]

The CQ bit was checked by ellyjones@chromium.org

[commit-bot: I haz the power, 2015-03-02 18:48:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/962373002/1

[commit-bot: I haz the power, 2015-03-02 19:57:16]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-02 19:57:58]

Patchset 1 (id:??) landed as
https://crrev.com/d83ea6db85677c1732c230d40b2af9b3da433228
Cr-Commit-Position: refs/heads/master@{#318739}