Mark gtest and gmock as testonly in GN.

media/base/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/arm.gni")
 import("//build/config/ui.gni")
 import("//build/config/linux/pkg_config.gni")
 import("//media/media_options.gni")
 
@@ skipping 206 matching lines @@
 
   if (is_linux || is_win) {
     sources += [
       "keyboard_event_counter.cc",
       "keyboard_event_counter.h",
     ]
   }
 }
 
 source_set("test_support") {
+  testonly = true
   sources = [
     "fake_audio_render_callback.cc",
     "fake_audio_render_callback.h",
     "fake_audio_renderer_sink.cc",
     "fake_audio_renderer_sink.h",
     "fake_text_track_stream.cc",
     "fake_text_track_stream.h",
     "gmock_callback_support.h",
     "mock_audio_renderer_sink.cc",
     "mock_audio_renderer_sink.h",
     "mock_demuxer_host.cc",
     "mock_demuxer_host.h",
     "mock_filters.cc",
     "mock_filters.h",
     "test_data_util.cc",
     "test_data_util.h",
     "test_helpers.cc",
     "test_helpers.h",
   ]
   configs += [ "//media:media_config" ]
   deps = [ "//testing/gmock" ]
 }
 
 source_set("unittests") {
+  testonly = true
   sources = [
     "audio_block_fifo_unittest.cc",
     "audio_buffer_converter_unittest.cc",
     "audio_buffer_unittest.cc",
     "audio_buffer_queue_unittest.cc",
     "audio_bus_unittest.cc",
     "audio_converter_unittest.cc",
     "audio_discard_helper_unittest.cc",
     "audio_fifo_unittest.cc",
     "audio_hardware_config_unittest.cc",
@@ skipping 56 matching lines @@
   } else {
     deps += [ "//ui/gl" ]
   }
 
   if (cpu_arch == "x86" || cpu_arch == "x64") {
     sources += [ "simd/convert_rgb_to_yuv_unittest.cc" ]
   }
 }
 
 source_set("perftests") {
+  testonly = true
   sources = [
     "audio_bus_perftest.cc",
     "audio_converter_perftest.cc",
     "run_all_perftests.cc",
     "sinc_resampler_perftest.cc",
     "vector_math_perftest.cc",
     "yuv_convert_perftest.cc",
   ]
   configs += [ "//media:media_config" ]
   deps = [
@@ skipping 78 matching lines @@
       if (is_posix) {
         yasm_flags += [ "-DELF" ]
         if (cpu_arch == "x64") {
         # TODO(ajwong): Why isn't this true in mac?
           yasm_flags += [ "-DPIC" ]
         }
       }
     }
   }
 }