mac/gn: Make a bunch of targets build in release 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("//build/config/android/config.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//third_party/protobuf/proto_library.gni")
 
@@ skipping 525 matching lines @@
       "//base",
       "//media",
     ]
   }
 }
 
 # Projects external to Chromium can build cast_sender and/or cast_receiver to
 # produce libraries to link with their applications.  Chromium targets should
 # not reference these.
 
-static_library("cast_sender") {
+group("cast_sender") {

[Nico, 2016/05/13 21:03:47]

actually, i think this change is wrong

   deps = [
     ":sender",
   ]
 }
 
-static_library("cast_receiver") {
+group("cast_receiver") {
   deps = [
     ":receiver",
   ]
 }