Andrew MacDonald e2357149eb Guard new protobuf target with enable_protobuf==1.
Fixes a gyp error on iOS.

BUG=4642
TBR=aluebs@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/46229004

Cr-Commit-Position: refs/heads/master@{#9180}
2015-05-12 15:43:38 +00:00
..
2015-05-12 13:04:29 +00:00
2015-05-11 08:17:46 +00:00