Add CreatePeerConnectionFactory overloads that take audio codec factory args

webrtc/pc/test/mock_peerconnection.h

Index: webrtc/pc/test/mock_peerconnection.h
diff --git a/webrtc/pc/test/mock_peerconnection.h b/webrtc/pc/test/mock_peerconnection.h
index 4dca0afad47f468b5920dbc8dd6c34e0e9fd1f3e..97f31c1673870dc4079846de84a664c2657bee30 100644
--- a/webrtc/pc/test/mock_peerconnection.h
+++ b/webrtc/pc/test/mock_peerconnection.h
@@ -20,7 +20,12 @@ namespace webrtc {
 
 // The factory isn't really used; it just satisfies the base PeerConnection.
 class FakePeerConnectionFactory
-    : public rtc::RefCountedObject<webrtc::PeerConnectionFactory> {};
+    : public rtc::RefCountedObject<webrtc::PeerConnectionFactory> {
+ public:
+  FakePeerConnectionFactory()
+      : rtc::RefCountedObject<webrtc::PeerConnectionFactory>(nullptr, nullptr) {
+  }
+};
 
 class MockPeerConnection
     : public rtc::RefCountedObject<webrtc::PeerConnection> {