[Cast] VideoFrameFactory interface to vend frames with encoder affinity.

media/cast/sender/video_sender_unittest.cc

Index: media/cast/sender/video_sender_unittest.cc
diff --git a/media/cast/sender/video_sender_unittest.cc b/media/cast/sender/video_sender_unittest.cc
index 120d8c7678b624c30f2317f327607fc66617b083..2e55a1c5761cabbed8542895ec3d7a92d0bb4acc 100644
--- a/media/cast/sender/video_sender_unittest.cc
+++ b/media/cast/sender/video_sender_unittest.cc
@@ -15,6 +15,7 @@
 #include "media/cast/net/cast_transport_config.h"
 #include "media/cast/net/cast_transport_sender_impl.h"
 #include "media/cast/net/pacing/paced_sender.h"
+#include "media/cast/sender/video_frame_factory.h"
 #include "media/cast/sender/video_sender.h"
 #include "media/cast/test/fake_single_thread_task_runner.h"
 #include "media/cast/test/fake_video_encode_accelerator.h"
@@ -536,5 +537,10 @@ TEST_F(VideoSenderTest, AcksCancelRetransmits) {
   EXPECT_EQ(0, transport_.number_of_rtp_packets());
 }
 
+TEST_F(VideoSenderTest, CheckVideoFrameFactoryIsNull) {
+  EXPECT_EQ(STATUS_VIDEO_INITIALIZED, InitEncoder(false, true));
+  EXPECT_EQ(nullptr, video_sender_->CreateVideoFrameFactory().get());
+}
+
 }  // namespace cast
 }  // namespace media