Suppress obsolete co19 shadow dom event test on Chrome

BUG=

Review URL: https://codereview.chromium.org/1936583002 .

Author: alan-knight

tests/co19/co19-dart2js.status

@@ -1473,6 +1473,7 @@ WebPlatformTest/shadow-dom/events/event-retargeting/test-002_t01: RuntimeError #
 WebPlatformTest/shadow-dom/events/event-retargeting/test-004_t01: RuntimeError # Please triage this failure
 WebPlatformTest/shadow-dom/events/events-that-are-always-stopped/test-004_t01: RuntimeError # Please triage this failure
 WebPlatformTest/shadow-dom/events/events-that-are-always-stopped/test-005_t01: RuntimeError # Please triage this failure
+WebPlatformTest/shadow-dom/events/events-that-are-always-stopped/test-006_t01: RuntimeError # Issue 52
 WebPlatformTest/shadow-dom/events/events-that-are-always-stopped/test-007_t01: RuntimeError # Please triage this failure
 WebPlatformTest/shadow-dom/events/retargeting-focus-events/test-001_t01: Skip # Times out. Please triage this failure
 WebPlatformTest/shadow-dom/events/retargeting-focus-events/test-001_t02: Skip # Times out. Please triage this failure