Move gn _run target generation into test().

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 281 matching lines @@
   # details.  http://crbug.com/558714
   if (!is_android && !is_chromecast) {
     sources += [
       "test/fake_media_source.cc",
       "test/fake_media_source.h",
     ]
     deps += [ "//third_party/ffmpeg" ]
   }
 }
 
-# TODO(GYP): Delete this after we've converted everything to GN.
-# The _run targets exist only for compatibility w/ GYP.
-group("cast_unittests_run") {
-  testonly = true
-  deps = [
-    ":cast_unittests",
-  ]
-}
-
 test("cast_unittests") {
   sources = [
     "common/expanded_value_base_unittest.cc",
     "common/rtp_time_unittest.cc",
     "logging/encoding_event_subscriber_unittest.cc",
     "logging/receiver_time_offset_estimator_impl_unittest.cc",
     "logging/serialize_deserialize_test.cc",
     "logging/simple_event_subscriber_unittest.cc",
     "logging/stats_event_subscriber_unittest.cc",
     "net/cast_transport_sender_impl_unittest.cc",
@@ skipping 229 matching lines @@
   deps = [
     ":sender",
   ]
 }
 
 static_library("cast_receiver") {
   deps = [
     ":receiver",
   ]
 }