Bug 918220. Part 1. Rename the pref content.image.allow_locking to make it clear that it only applies to content processes. r=jmuizelaar
Bug 918220. Part 2. Remove image.mem.allow_locking_in_content_processes pref from fennec pref file, it doesn't apply to fennec because it doesn't have content processes and could be confusing. Also, give the pref a default value in all.js. r=jmuizelaar