GN: Change rtc_source_set targets --> rtc_static_library

webrtc/media/BUILD.gn

 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/linux/pkg_config.gni")
 import("../build/webrtc.gni")
@@ skipping 24 matching lines @@
 if (is_linux && rtc_use_gtk) {
   pkg_config("gtk-lib") {
     packages = [
       "gobject-2.0",
       "gthread-2.0",
       "gtk+-2.0",
     ]
   }
 }
 
-rtc_source_set("rtc_media") {
+rtc_static_library("rtc_media") {
   defines = []
   libs = []
   deps = []
   sources = [
     "base/audiosource.h",
     "base/codec.cc",
     "base/codec.h",
     "base/cpuid.cc",
     "base/cpuid.h",
     "base/cryptoparams.h",
@@ skipping 307 matching lines @@
     deps += [
       # TODO(kjellander): Move as part of work in bugs.webrtc.org/4243.
       ":rtc_media",
       ":rtc_unittest_main",
       "../audio",
       "../base:rtc_base_tests_utils",
       "../system_wrappers:metrics_default",
     ]
   }
 }