Late initialize MediaController, for less resource i.e. ProcessThread, usage by PeerConnection.

webrtc/api/peerconnectioninterface_unittest.cc

Index: webrtc/api/peerconnectioninterface_unittest.cc
diff --git a/webrtc/api/peerconnectioninterface_unittest.cc b/webrtc/api/peerconnectioninterface_unittest.cc
index 701ab3c001e6ab1cc08fd2ad9046314dca5e8707..d2d565b0f7882d39f849b661150f23fd219794e8 100644
--- a/webrtc/api/peerconnectioninterface_unittest.cc
+++ b/webrtc/api/peerconnectioninterface_unittest.cc
@@ -2364,6 +2364,12 @@ class PeerConnectionMediaConfigTest : public testing::Test {
     scoped_refptr<PeerConnectionInterface> pc(
         pcf_->CreatePeerConnection(config, constraints, nullptr, nullptr,
                                    &observer_));
+    {
+      // The MediaController is lazy initialized so in order for the below
+      // expectations not to fail, we need to trigger creation.
+      rtc::scoped_refptr<RtpSenderInterface> sender(
+          pc->CreateSender(MediaStreamTrackInterface::kAudioKind, "foo_id"));
+    }
     EXPECT_TRUE(pc.get());
     EXPECT_TRUE(pcf_->create_media_controller_called_);
     return pcf_->create_media_controller_config_;