Convert some GN test support targets to static libs.

remoting/protocol/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/features.gni")
 import("//remoting/remoting_srcs.gni")
 
-source_set("protocol") {
+static_library("protocol") {
   sources = rebase_path(remoting_srcs_gypi_values.remoting_protocol_sources,
                         ".",
                         "//remoting")
 
   configs += [
     "//build/config:precompiled_headers",
     "//build/config/compiler:no_size_t_to_int_warning",
     "//build/config/compiler:wexit_time_destructors",
   ]
 
@@ skipping 24 matching lines @@
     } else {
       sources -= [
         "webrtc_connection_to_client.cc",
         "webrtc_transport.cc",
         "webrtc_video_stream.cc",
       ]
     }
   }
 }
 
-source_set("test_support") {
+static_library("test_support") {
   testonly = true
 
   sources = [
     "fake_authenticator.cc",
     "fake_authenticator.h",
     "fake_connection_to_client.cc",
     "fake_connection_to_client.h",
     "fake_connection_to_host.cc",
     "fake_connection_to_host.h",
     "fake_datagram_socket.cc",
@@ skipping 57 matching lines @@
     "webrtc_transport_unittest.cc",
   ]
 
   deps = [
     ":test_support",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }