Introduce struct MediaConfig, with construction-time settings.

talk/app/webrtc/peerconnectioninterface_unittest.cc

Index: talk/app/webrtc/peerconnectioninterface_unittest.cc
diff --git a/talk/app/webrtc/peerconnectioninterface_unittest.cc b/talk/app/webrtc/peerconnectioninterface_unittest.cc
index 2388e71c04de7560ab9aaa6a0ba656fa1af6ba89..34ba0a05c2fce2fa7143b17bf86bfa4a23f32ad2 100644
--- a/talk/app/webrtc/peerconnectioninterface_unittest.cc
+++ b/talk/app/webrtc/peerconnectioninterface_unittest.cc
@@ -2355,6 +2355,45 @@ TEST_F(PeerConnectionInterfaceTest, SignalSameTracksInSeparateMediaStream) {
   EXPECT_TRUE(ContainsSender(senders, kVideoTracks[0]));
 }
 
+class PeerConnectionFactoryForTest : public webrtc::PeerConnectionFactory {
+ public:
+  webrtc::MediaControllerInterface* CreateMediaController(
+      const cricket::MediaConfig &config) const override {
+    createmediacontroller_called = true;
+    createmediacontroller_config = config;
+
+    webrtc::MediaControllerInterface* mc =
+        PeerConnectionFactory::CreateMediaController(config);
+    EXPECT_TRUE(mc != nullptr);
+    return mc;
+  }
+
+  mutable bool createmediacontroller_called = false;

[pbos-webrtc, 2016/02/09 15:31:43]

create_media_controller_called

[perkj_webrtc, 2016/02/09 15:35:37]

member variables should end with _, iereatemediacontroller_called_

[perkj_webrtc, 2016/02/09 15:35:37]

why mutable  ?

[nisse-webrtc, 2016/02/10 08:53:00]

The CreateMediaController method is const. So I need to cheat to be able to
modify those members. One alternative is to move the variables out to a separate
struct and keep a reference to them, but using mutable seems simpler.

[nisse-webrtc, 2016/02/10 08:53:00]

Done.

[nisse-webrtc, 2016/02/10 08:53:00]

Done.

+  mutable cricket::MediaConfig createmediacontroller_config;

[perkj_webrtc, 2016/02/09 15:35:37]

dito

+};
+
+// This test verifies DSCP constraint is recognized and passed to the
+// CreateMediaController.
+TEST(PeerConnection, TestDscpConstraint) {

[pbos-webrtc, 2016/02/09 15:31:43]

Can you add tests for the other options as well? 

[nisse-webrtc, 2016/02/10 08:53:00]

I guess so. We just need to find the right balance. There are two constraints
which can be true, false or unset. And one flag copied from RTCConfiguration. So
a total of 18 combinations. 

I'm adding code to test a few selected combinations.

+  scoped_refptr<PeerConnectionFactoryForTest> pcf(
+      new rtc::RefCountedObject<PeerConnectionFactoryForTest>());
+  PeerConnectionInterface::RTCConfiguration config;
+  FakeConstraints constraints;
+  MockPeerConnectionObserver observer;

[perkj_webrtc, 2016/02/09 15:35:37]

move to where it is used.

+  scoped_refptr<PeerConnectionInterface> pc;

[perkj_webrtc, 2016/02/09 15:35:37]

declare when used.

+  constraints.AddOptional(
+      webrtc::MediaConstraintsInterface::kEnableDscp, true);

[perkj_webrtc, 2016/02/09 15:35:37]

also test calling with kEnableDscp false ?

+  pcf->Initialize();
+
+  EXPECT_FALSE(pcf->createmediacontroller_config.enable_dscp);
+
+  pc = pcf->CreatePeerConnection(config, &constraints,
+                                 nullptr, nullptr, &observer);
+  EXPECT_TRUE(pc.get() != nullptr);
+  EXPECT_TRUE(pcf->createmediacontroller_called);
+  EXPECT_TRUE(pcf->createmediacontroller_config.enable_dscp);
+}
+
 // The following tests verify that session options are created correctly.
 // TODO(deadbeef): Convert these tests to be more end-to-end. Instead of
 // "verify options are converted correctly", should be "pass options into