Convert test_support source sets to static libs

components/data_reduction_proxy/core/browser/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.
 
 browser_sources = [
   "data_reduction_proxy_bypass_protocol.cc",
   "data_reduction_proxy_bypass_protocol.h",
   "data_reduction_proxy_bypass_stats.cc",
   "data_reduction_proxy_bypass_stats.h",
   "data_reduction_proxy_compression_stats.cc",
@@ skipping 78 matching lines @@
     "//third_party/leveldatabase",
     "//url",
   ]
 
   defines = [ "USE_GOOGLE_API_KEYS" ]
   if (!is_ios) {
     defines += [ "USE_GOOGLE_API_KEYS_FOR_AUTH_KEY" ]
   }
 }
 
-source_set("test_support") {
+static_library("test_support") {
   testonly = true
   sources = [
     "data_reduction_proxy_config_test_utils.cc",
     "data_reduction_proxy_config_test_utils.h",
     "data_reduction_proxy_settings_test_utils.cc",
     "data_reduction_proxy_settings_test_utils.h",
     "data_reduction_proxy_test_utils.cc",
     "data_reduction_proxy_test_utils.h",
   ]
 
@@ skipping 67 matching lines @@
     "//base/test:test_support",
     "//components/data_reduction_proxy/core/common:test_support",
     "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//components/prefs:test_support",
     "//components/variations",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }