sheriff: disable IncrementalMarkingTest.StepDuringMixinObjectConstruction

Bug: 1073157
Change-Id: Id3171b2e58baed0711f873adc1e41783415c30a4
Tbr: mlippautz@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2159572Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#761069}

third_party/blink/renderer/platform/heap/incremental_marking_test.cc

@@ -6,6 +6,7 @@
 
 #include "base/bind.h"
 #include "base/test/scoped_feature_list.h"
+#include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/blink/public/common/features.h"
 #include "third_party/blink/renderer/platform/bindings/script_forbidden_scope.h"
@@ -1651,7 +1652,16 @@ TEST_F(IncrementalMarkingTest, StepDuringObjectConstruction) {
   PreciselyCollectGarbage();
 }
 
-TEST_F(IncrementalMarkingTest, StepDuringMixinObjectConstruction) {
+#if defined(OS_LINUX) && defined(THREAD_SANITIZER)
+// Flaky under linux tsan: https://crbug.com/1073157
+#define MAYBE_StepDuringMixinObjectConstruction \
+  DISABLED_StepDuringMixinObjectConstruction
+#else
+#define MAYBE_StepDuringMixinObjectConstruction \
+  StepDuringMixinObjectConstruction
+#endif
+
+TEST_F(IncrementalMarkingTest, MAYBE_StepDuringMixinObjectConstruction) {
   // Test ensures that mixin objects in construction are delayed for processing
   // to allow omitting write barriers on initializing stores.