Revert of Fix errors found in Mac gn component builds

media/cast/BUILD.gn

Index: media/cast/BUILD.gn
diff --git a/media/cast/BUILD.gn b/media/cast/BUILD.gn
index b6df09f4e874838ae7bbf76433b65d26749229be..2262c7b6cbc5f3e6d78c2c0712002865fc0681d9 100644
--- a/media/cast/BUILD.gn
+++ b/media/cast/BUILD.gn
@@ -163,24 +163,11 @@
     ]
   }
 
-  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",
     ]
   }
 }