Introduce struct MediaConfig, with construction-time settings.

webrtc/api/webrtcsession_unittest.cc

Index: webrtc/api/webrtcsession_unittest.cc
diff --git a/webrtc/api/webrtcsession_unittest.cc b/webrtc/api/webrtcsession_unittest.cc
index 8bbcb58dd8699ed81127f64c960a43843d5c2c6e..609ef5009abc35f6c65fd82ea3b0969fa2eccea9 100644
--- a/webrtc/api/webrtcsession_unittest.cc
+++ b/webrtc/api/webrtcsession_unittest.cc
@@ -329,7 +329,8 @@ class WebRtcSessionTest
                                         rtc::Thread::Current())),
         fake_call_(webrtc::Call::Config()),
         media_controller_(
-            webrtc::MediaControllerInterface::Create(rtc::Thread::Current(),
+            webrtc::MediaControllerInterface::Create(cricket::MediaConfig(),
+                                                     rtc::Thread::Current(),
                                                      channel_manager_.get())),
         tdesc_factory_(new cricket::TransportDescriptionFactory()),
         desc_factory_(
@@ -4039,28 +4040,6 @@ TEST_F(WebRtcSessionTest, TestSetRemoteOfferFailIfDtlsDisabledAndNoCrypto) {
                                        offer);
 }
 
-// This test verifies DSCP is properly applied on the media channels.
-TEST_F(WebRtcSessionTest, TestDscpConstraint) {
-  constraints_.reset(new FakeConstraints());
-  constraints_->AddOptional(
-      webrtc::MediaConstraintsInterface::kEnableDscp, true);
-  Init();
-  SendAudioVideoStream1();
-  SessionDescriptionInterface* offer = CreateOffer();
-
-  SetLocalDescriptionWithoutError(offer);
-
-  video_channel_ = media_engine_->GetVideoChannel(0);
-  voice_channel_ = media_engine_->GetVoiceChannel(0);
-
-  ASSERT_TRUE(video_channel_ != NULL);
-  ASSERT_TRUE(voice_channel_ != NULL);
-  const cricket::AudioOptions& audio_options = voice_channel_->options();
-  const cricket::VideoOptions& video_options = video_channel_->options();
-  EXPECT_EQ(rtc::Optional<bool>(true), audio_options.dscp);
-  EXPECT_EQ(rtc::Optional<bool>(true), video_options.dscp);
-}
-
 TEST_F(WebRtcSessionTest, TestSuspendBelowMinBitrateConstraint) {
   constraints_.reset(new FakeConstraints());
   constraints_->AddOptional(