Fix errors found in Mac gn component builds

media/cast/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.
 
 import("//testing/test.gni")
 
 component("cast") {
   deps = [
     ":sender",
     ":receiver",
@@ skipping 145 matching lines @@
     sources -= [
       "sender/external_video_encoder.cc",
       "sender/external_video_encoder.h",
       "sender/video_encoder_impl.cc",
       "sender/video_encoder_impl.h",
       "sender/vp8_encoder.cc",
       "sender/vp8_encoder.h",
     ]
   }
 
+  libs = []
+
   # iOS and OS X encoders
   if (is_ios || is_mac) {
     sources += [
       "sender/h264_vt_encoder.cc",
       "sender/h264_vt_encoder.h",
     ]
+
+    libs += [
+      "CoreVideo.framework",
+    ]
+  }
+
+  if (is_mac) {
+    # Required by audio_encoder.cc.
+    libs += [
+      "AudioToolbox.framework",
+    ]
   }
 }
 
 source_set("receiver") {
   sources = [
     "cast_receiver.h",
     "receiver/audio_decoder.cc",
     "receiver/audio_decoder.h",
     "receiver/cast_receiver_impl.cc",
     "receiver/cast_receiver_impl.h",
@@ skipping 223 matching lines @@
       "test/utility/tap_proxy.cc",
     ]
 
     deps = [
       ":test_support",
       "//base",
       "//media",
     ]
   }
 }