active_map_test: remove unused VP9_FACTORY define

Change-Id: If96a133ad83e3ed4e4b3620dff857b26641da892
diff --git a/test/active_map_test.cc b/test/active_map_test.cc
index 6377e72..a9bb540 100644
--- a/test/active_map_test.cc
+++ b/test/active_map_test.cc
@@ -83,9 +83,6 @@
   ASSERT_NO_FATAL_FAILURE(RunLoop(&video));
 }
 
-#define VP9_FACTORY \
-  static_cast<const libvpx_test::CodecFactory *>(&libvpx_test::kVP9)
-
 VP9_INSTANTIATE_TEST_CASE(ActiveMapTest,
                           ::testing::Values(::libvpx_test::kRealTime),
                           ::testing::Range(0, 6));