Bug 853356 - Part1 Add new permissions and prompt for mutiple permissions request. r=fabrice, felipc, wjohnston, mrbkap, jimm
Bug 853356 - Part2 Add MediaPermissionGonk.h and MediaPermissionGonk.cpp to implement ContentPermissionPrompt. r=jesup
Bug 853356 - Part3 Pass a string array instead of a single string to support multiple permissions request. r=khuey
Bug 853356 - Test: Check mediastream track according to request type. r=jsmith