Add utility set classes to support getUserMedia constraint proccessing.

content/test/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/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
@@ skipping 1558 matching lines @@
       "../browser/webrtc/webrtc_internals_unittest.cc",
       "../renderer/media/audio_repetition_detector_unittest.cc",
       "../renderer/media/capturefromelement/canvas_capture_handler_unittest.cc",
       "../renderer/media/capturefromelement/html_audio_element_capturer_source_unittest.cc",
       "../renderer/media/capturefromelement/html_video_element_capturer_source_unittest.cc",
       "../renderer/media/gpu/rtc_video_decoder_unittest.cc",
       "../renderer/media/gpu/rtc_video_encoder_unittest.cc",
       "../renderer/media/media_devices_event_dispatcher_unittest.cc",
       "../renderer/media/media_stream_audio_processor_unittest.cc",
       "../renderer/media/media_stream_audio_unittest.cc",
+      "../renderer/media/media_stream_constraints_util_sets_unittest.cc",
       "../renderer/media/media_stream_constraints_util_unittest.cc",
       "../renderer/media/media_stream_constraints_util_video_device_unittest.cc",
       "../renderer/media/media_stream_dispatcher_unittest.cc",
       "../renderer/media/media_stream_video_capturer_source_unittest.cc",
       "../renderer/media/media_stream_video_renderer_sink_unittest.cc",
       "../renderer/media/media_stream_video_source_unittest.cc",
       "../renderer/media/media_stream_video_track_unittest.cc",
       "../renderer/media/mock_constraint_factory.cc",
       "../renderer/media/mock_media_stream_registry.cc",
       "../renderer/media/mock_media_stream_registry.h",
@@ skipping 232 matching lines @@
   if (is_android) {
     deps += [ "//testing/android/native_test:native_test_native_code" ]
   }
 }
 
 group("fuzzers") {
   deps = [
     "//content/test/fuzzer",
   ]
 }