Bring back -fstack-protector-all on iOS.

Bring back -fstack-protector-all on iOS.

This flag used to cause a crash on startup. As of Xcode 5 this doesn't
appear to happen anymore.

BUG=341484
TEST=None

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=255263

[justincohen, 2014-03-05 20:32:49]

We brought this back on iOS builds and haven't seen any issues.  PTAL!

[Mark Mentovai, 2014-03-05 20:40:36]

Great! LGTM.

[justincohen, 2014-03-05 20:59:06]

The CQ bit was checked by justincohen@chromium.org

[commit-bot: I haz the power, 2014-03-05 20:59:49]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/justincohen@chromium.org/187823005/1

[commit-bot: I haz the power, 2014-03-06 00:00:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/justincohen@chromium.org/187823005/1

[commit-bot: I haz the power, 2014-03-06 02:41:44]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/justincohen@chromium.org/187823005/1

[commit-bot: I haz the power, 2014-03-06 03:11:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/justincohen@chromium.org/187823005/1

[commit-bot: I haz the power, 2014-03-06 05:41:41]

Change committed as 255263

[Ami GONE FROM CHROMIUM, 2014-03-20 21:47:10]

Post-commit heads-up: this broke the WebRTC-on-iOS standalone build (chrome/ios
doesn't support webrtc).  Please follow along in
https://code.google.com/p/webrtc/issues/detail?id=3067 if interested.