[Mac/GN] Set up the component build.

third_party/decklink/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # GYP version: //third_party/decklink/decklink.gyp:decklink
 if (is_mac) {
   static_library("decklink") {
     sources = [
       "mac/include/DeckLinkAPIDispatch.cpp",
     ]
+    libs = [
+      "CoreFoundation.framework",
+      "IOKit.framework",
+    ]
   }
 }