Fix unit test failure

The test if for non real-time only.

BUG=aomedia:3055

Change-Id: Icf1ab4f824a046bb6ff19aafc3045313a48b9b19
diff --git a/test/av1_external_partition_test.cc b/test/av1_external_partition_test.cc
index 8a1d1c5..dbad066 100644
--- a/test/av1_external_partition_test.cc
+++ b/test/av1_external_partition_test.cc
@@ -21,6 +21,7 @@
 #include "test/util.h"
 
 #if CONFIG_AV1_ENCODER
+#if !CONFIG_REALTIME_ONLY
 namespace {
 
 constexpr int kFrameNum = 8;
@@ -174,4 +175,5 @@
                            ::testing::Values(4));  // cpu_used
 
 }  // namespace
+#endif  // !CONFIG_REALTIME_ONLY
 #endif  // CONFIG_AV1_ENCODER
diff --git a/test/test.cmake b/test/test.cmake
index e0ee908..8b276c5 100644
--- a/test/test.cmake
+++ b/test/test.cmake
@@ -96,6 +96,7 @@
 
 if(CONFIG_REALTIME_ONLY)
   list(REMOVE_ITEM AOM_UNIT_TEST_ENCODER_SOURCES
+                   "${AOM_ROOT}/test/av1_external_partition_test.cc"
                    "${AOM_ROOT}/test/borders_test.cc"
                    "${AOM_ROOT}/test/cpu_speed_test.cc"
                    "${AOM_ROOT}/test/end_to_end_test.cc"