Add explicit AppKit dependency for obs/platform-osx

cmake/Modules/FindAppKit.cmake

@@ -0,0 +1,17 @@
+# Once done these will be defined:
+#
+#  AppKit_FOUND
+#  AppKit_LIBRARIES
+#
+
+if(AppKit_INCLUDE_DIR AND Libavutil_LIBRARIES)
+	set(AppKit_FOUND TRUE)
+else()
+	find_library(APPKIT_FRAMEWORK AppKit)
+
+	set(AppKit_LIBRARIES ${APPKIT_FRAMEWORK} CACHE STRING "AppKit framework")
+
+	find_package_handle_standard_args(AppKit DEFAULT_MSG APPKIT_FRAMEWORK)
+	mark_as_advanced(APPKIT_FRAMEWORK)
+endif()
+

obs/CMakeLists.txt

@@ -25,6 +25,10 @@ if(WIN32)
 elseif(APPLE)
 	set(obs_PLATFORM_SOURCES
 		platform-osx.mm)
+
+	find_package(AppKit REQUIRED)
+	set(obs_PLATFORM_LIBRARIES ${AppKit_LIBRARIES})
+
 	add_definitions(-fobjc-arc)
 elseif(UNIX)
 	set(obs_PLATFORM_SOURCES