Summary:
This diff runs CLANGFORMAT lint on plugins. I have added CLANGFORMAT as the lint engined for objc files in xplat/sonar. Right now the iOS folder is not formatted according to CLANGFORMAT.
Ran `arc lint -a --paths-cmd "find ./iOS/Plugins -type f" --verbose`
Reviewed By: passy
Differential Revision: D19942173
fbshipit-source-id: 8b975b0a344df073b02d69cd1f9ee5629af2799d
e8b20d5b15