Simplify passing video codec factories in media engine

webrtc/media/base/videoengine_unittest.h

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 46 matching lines @@
 inline bool IsEqualCodec(const cricket::VideoCodec& a,
                          const cricket::VideoCodec& b) {
   return a.id == b.id && a.name == b.name;
 }
 
 template<class E, class C>
 class VideoMediaChannelTest : public testing::Test,
                               public sigslot::has_slots<> {
  protected:
   VideoMediaChannelTest<E, C>()
-      : call_(webrtc::Call::Create(webrtc::Call::Config(&event_log_))) {}
+      : call_(webrtc::Call::Create(webrtc::Call::Config(&event_log_))),
+        engine_(nullptr /* external_encoder_factory */,
+                nullptr /* external_decoder_factory */) {}
 
   virtual cricket::VideoCodec DefaultCodec() = 0;
 
   virtual cricket::StreamParams DefaultSendStreamParams() {
     return cricket::StreamParams::CreateLegacy(kSsrc);
   }
 
   virtual void SetUp() {
-    engine_.Init();
     cricket::MediaConfig media_config;
     // Disabling cpu overuse detection actually disables quality scaling too; it
     // implies DegradationPreference kMaintainResolution. Automatic scaling
     // needs to be disabled, otherwise, tests which check the size of received
     // frames become flaky.
     media_config.video.enable_cpu_overuse_detection = false;
     channel_.reset(engine_.CreateChannel(call_.get(), media_config,
                                          cricket::VideoOptions()));
     channel_->OnReadyToSend(true);
     EXPECT_TRUE(channel_.get() != NULL);
@@ skipping 849 matching lines @@
   std::unique_ptr<C> channel_;
   cricket::FakeNetworkInterface network_interface_;
   cricket::FakeVideoRenderer renderer_;
   cricket::VideoMediaChannel::Error media_error_;
 
   // Used by test cases where 2 streams are run on the same channel.
   cricket::FakeVideoRenderer renderer2_;
 };
 
 #endif  // WEBRTC_MEDIA_BASE_VIDEOENGINE_UNITTEST_H_  NOLINT