Fix release builds for iOS. Add stub chromium impl for preferences.

Fix release builds for iOS. Add stub chromium impl for preferences.

BUG=711612
Review-Url: https://codereview.chromium.org/2818153002
Cr-Commit-Position: refs/heads/master@{#464763}
Committed: https://chromium.googlesource.com/chromium/src/+/3b1c2e7db1894fcb07f104d17343fa6912be2188

[nicholss, 2017-04-14 17:33:02]

nicholss@chromium.org changed reviewers:
+ jamiewalch@chromium.org

[nicholss, 2017-04-14 17:33:02]

PTAL, band-aid to fix the release.

[Jamie, 2017-04-14 17:41:33]

lgtm

[nicholss, 2017-04-14 17:41:55]

The CQ bit was checked by nicholss@chromium.org

[commit-bot: I haz the power, 2017-04-14 17:42:23]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-14 18:52:54]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1492191715993070, "parent_rev":
"335760818a29274b57f59d23f555bf6a3b60fb3e", "commit_rev":
"3b1c2e7db1894fcb07f104d17343fa6912be2188"}

[commit-bot: I haz the power, 2017-04-14 18:53:55]

Description was changed from

==========
Fix release builds for iOS. Add stub chromium impl for preferences.

BUG=711612
==========

to

==========
Fix release builds for iOS. Add stub chromium impl for preferences.

BUG=711612

Review-Url: https://codereview.chromium.org/2818153002
Cr-Commit-Position: refs/heads/master@{#464763}
Committed:
https://chromium.googlesource.com/chromium/src/+/3b1c2e7db1894fcb07f104d17343...
==========

[commit-bot: I haz the power, 2017-04-14 18:53:56]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/3b1c2e7db1894fcb07f104d17343...