Mark http/tests/security/cross-origin-indexeddb-allowed.html as flaky

Bug: 934636
Change-Id: Ica9965dc176845f7f90aa6950eda3b25063126ce
Tbr: mkwst@chromium.org
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/1482292
Auto-Submit: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Mike West <mkwst@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634586}

third_party/blink/web_tests/TestExpectations

@@ -6001,3 +6001,9 @@ crbug.com/933346 [ Debug ] external/wpt/orientation-sensor/RelativeOrientationSe
 
 # Sheriff 2019-02-21
 crbug.com/934278 [ Mac ] virtual/video-surface-layer/media/video-object-fit.html [ Failure Pass ]
+
+# Sheriff 2019-02-22
+crbug.com/934636 http/tests/security/cross-origin-indexeddb-allowed.html [ Crash Pass ]
+crbug.com/934636 virtual/feature-policy-for-sandbox/http/tests/security/cross-origin-indexeddb-allowed.html [ Crash Pass ]
+crbug.com/934636 virtual/outofblink-cors/http/tests/security/cross-origin-indexeddb-allowed.html [ Crash Pass ]
+crbug.com/934636 virtual/outofblink-cors-ns/http/tests/security/cross-origin-indexeddb-allowed.html [ Crash Pass ]