Added support for GameController devices on OSX

device/gamepad/BUILD.gn

Index: device/gamepad/BUILD.gn
diff --git a/device/gamepad/BUILD.gn b/device/gamepad/BUILD.gn
index 6e6e00066293e33f4545db6bd7f3518f5fe237e9..92cc1d34e31ae5e0d0c60de2799832ba882cc798 100644
--- a/device/gamepad/BUILD.gn
+++ b/device/gamepad/BUILD.gn
@@ -15,6 +15,8 @@ component("gamepad") {
   sources = [
     "android/gamepad_jni_registrar.cc",
     "android/gamepad_jni_registrar.h",
+    "game_controller_data_fetcher_mac.h",
+    "game_controller_data_fetcher_mac.mm",
     "gamepad_consumer.cc",
     "gamepad_consumer.h",
     "gamepad_data_fetcher.cc",
@@ -73,8 +75,11 @@ component("gamepad") {
     libs = [
       "CoreFoundation.framework",
       "Foundation.framework",
+      "GameController.framework",
       "IOKit.framework",
     ]
+
+    cflags = [ "-Wpartial-availability" ]
   }
 }