Disable ENABLE_BITCODE for iOS 9.

Disable ENABLE_BITCODE for iOS 9.

We don't support bitcode yet and open source version of clang does not
support the embed-bitcode-marker flag.
Turn off bitcode at the moment.

BUG=516530
Committed: https://crrev.com/628601cd3665668cc197b3c3b4f56bba68b131ae
Cr-Commit-Position: refs/heads/master@{#342316}

[Olivier, 2015-08-05 11:24:56]

olivierrobin@chromium.org changed reviewers:
+ justincohen@chromium.org, sdefresne@chromium.org, thakis@chromium.org

[sdefresne, 2015-08-05 12:29:05]

lgtm

[justincohen, 2015-08-06 20:39:50]

justincohen@chromium.org changed reviewers:
+ dpranke@google.com, scottmg@chromium.org

[justincohen, 2015-08-06 20:39:50]

dpranke or scottmg for OWNERS.

[Dirk Pranke, 2015-08-06 20:40:44]

dpranke@chromium.org changed reviewers:
+ dpranke@chromium.org

[Dirk Pranke, 2015-08-06 20:40:44]

lgtm

[justincohen, 2015-08-06 20:43:00]

The CQ bit was checked by justincohen@chromium.org

[commit-bot: I haz the power, 2015-08-06 20:44:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1265373003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1265373003/1

[commit-bot: I haz the power, 2015-08-06 21:53:30]

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

[commit-bot: I haz the power, 2015-08-06 21:53:30]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[sdefresne, 2015-08-07 07:06:00]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2015-08-07 07:06:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1265373003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1265373003/1

[sdefresne, 2015-08-07 07:06:16]

sdefresne@chromium.org changed reviewers:
- dpranke@google.com

[commit-bot: I haz the power, 2015-08-07 07:46:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-07 07:47:26]

Patchset 1 (id:??) landed as
https://crrev.com/628601cd3665668cc197b3c3b4f56bba68b131ae
Cr-Commit-Position: refs/heads/master@{#342316}