Remove chrome.principals API

Remove chrome.principals API

It was never implemented or used; a replacement for the
principalsPrivate extension API. It's been untouched for over a year.

BUG=463335
Committed: https://crrev.com/511c501ba80de0a1dd08f8a31701083b90fb4af8
Cr-Commit-Position: refs/heads/master@{#320777}

[Ryan Sleevi, 2015-03-03 01:35:04]

rsleevi@chromium.org changed reviewers:
+ rogerta@chromium.org

[Ryan Sleevi, 2015-03-03 01:35:05]

Roger: Death to dead code. If we can remove principalsPrivate as well (which
crbug.com/298164 suggests we should be able to), that's even better!

[Roger Tawa OOO till Jul 10th, 2015-03-10 13:55:16]

lgtm

OK to remove this code for now.  We still need a way to expose this information
to web pages, but I'll talk to the OWP/fizz folks to see if there is a better
way.

[Ryan Sleevi, 2015-03-10 17:05:43]

rsleevi@chromium.org changed reviewers:
+ thestig@chromium.org

[Ryan Sleevi, 2015-03-10 17:05:43]

thestig@chromium.org: Please review changes in 

chrome/renderer

[Lei Zhang, 2015-03-10 19:27:27]

lgtm

[Ryan Sleevi, 2015-03-10 19:31:39]

The CQ bit was checked by rsleevi@chromium.org

[commit-bot: I haz the power, 2015-03-10 19:31:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/970043002/1

[commit-bot: I haz the power, 2015-03-10 19:35:29]

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

[commit-bot: I haz the power, 2015-03-10 19:35:30]

Try jobs failed on following builders:
  ios_dbg_simulator_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_dbg_simulator...)
  ios_rel_device_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)

[Ryan Sleevi, 2015-03-16 19:03:46]

The CQ bit was checked by rsleevi@chromium.org

[Ryan Sleevi, 2015-03-16 19:03:47]

The patchset sent to the CQ was uploaded after l-g-t-m from
thestig@chromium.org, rogerta@chromium.org
Link to the patchset: https://codereview.chromium.org/970043002/#ps40001 (title:
"Bad merge")

[commit-bot: I haz the power, 2015-03-16 19:04:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/970043002/40001

[commit-bot: I haz the power, 2015-03-16 19:47:12]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-03-16 19:47:42]

Patchset 3 (id:??) landed as
https://crrev.com/511c501ba80de0a1dd08f8a31701083b90fb4af8
Cr-Commit-Position: refs/heads/master@{#320777}