Revert "Re-enable MonochromeRealtimeTest"

This reverts commit 3b8a9b236fdc1d2a3091a347afab49d8adb15893.

Reason for revert: nightly test failure

Change-Id: Ib2cd377534eab7edbc27ac0e241696afe85196ca

test/monochrome_test.cc

diff --git a/test/monochrome_test.cc b/test/monochrome_test.cc
index 826b68d..cfc16d0 100644
--- a/test/monochrome_test.cc
+++ b/test/monochrome_test.cc
@@ -55,8 +55,6 @@
       encoder->Control(AOME_SET_CPUUSED, GET_PARAM(3));
       if (mode_ == ::libaom_test::kAllIntra) {
         encoder->Control(AOME_SET_CQ_LEVEL, kCqLevel);
-      } else if (mode_ == ::libaom_test::kRealTime) {
-        encoder->Control(AOME_SET_MAX_INTRA_BITRATE_PCT, 10000);
       }
       if (lossless_) {
         encoder->Control(AV1E_SET_LOSSLESS, 1);
@@ -183,7 +181,14 @@
 
 class MonochromeRealtimeTest : public MonochromeTest {};
 
-TEST_P(MonochromeRealtimeTest, TestMonochromeEncoding) {
+#if CONFIG_REALTIME_ONLY
+// TODO: https://crbug.com/aomedia/376504476 - Enable this test after large
+// PSNR differences are resolved in this configuration.
+#define MAYBE_TestMonochromeEncoding DISABLED_TestMonochromeEncoding
+#else
+#define MAYBE_TestMonochromeEncoding TestMonochromeEncoding
+#endif
+TEST_P(MonochromeRealtimeTest, MAYBE_TestMonochromeEncoding) {
   ::libaom_test::I420VideoSource video("hantro_collage_w352h288.yuv", 352, 288,
                                        30, 1, 0, 30);
   init_flags_ = AOM_CODEC_USE_PSNR;