Gardening: external/wpt/service-workers/service-worker/multipart-image.https.html is flaky

Bug: 813775
Change-Id: Ifb738ea32c6f06b20aabca21b540a1c39577300f
TBR: bashi
Reviewed-on: https://chromium-review.googlesource.com/926442Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537777}

third_party/WebKit/LayoutTests/TestExpectations

@@ -3285,6 +3285,10 @@ crbug.com/417782 virtual/threaded/http/tests/devtools/tracing/timeline-paint/tim
 # End of Root Layer Scrolling expectations
 ################################################################################
 
+crbug.com/813775 external/wpt/service-workers/service-worker/multipart-image.https.html [ Pass Failure ]
+crbug.com/813775 virtual/outofblink-cors/external/wpt/service-workers/service-worker/multipart-image.https.html [ Pass Failure ]
+crbug.com/813775 virtual/navigation-mojo-response/external/wpt/service-workers/service-worker/multipart-image.https.html [ Pass Failure ]
+
 crbug.com/813468 [ Mac ] virtual/navigation-mojo-response/http/tests/serviceworker/chromium/memory-cache.html [ Failure Pass ]
 
 # TODO(ricea): Remove these once fetch abort implementation is complete

third_party/WebKit/LayoutTests/platform/mac-mac10.10/virtual/outofblink-cors/external/wpt/service-workers/service-worker/multipart-image.https-expected.txt

-This is a testharness.js-based test.
-PASS initialize global state
-PASS same-origin multipart image via SW should be readable
-FAIL cross-origin multipart image via SW with approved CORS should be readable assert_equals: expected 255 but got 0
-PASS cross-origin multipart image with no-cors via SW should not be readable
-PASS cross-origin multipart image via SW with rejected CORS should fail to load
-PASS restore global state
-Harness: the test ran to completion.
-

third_party/WebKit/LayoutTests/platform/mac-retina/virtual/outofblink-cors/external/wpt/service-workers/service-worker/multipart-image.https-expected.txt

-This is a testharness.js-based test.
-PASS initialize global state
-PASS same-origin multipart image via SW should be readable
-FAIL cross-origin multipart image via SW with approved CORS should be readable assert_equals: expected 255 but got 0
-PASS cross-origin multipart image with no-cors via SW should not be readable
-PASS cross-origin multipart image via SW with rejected CORS should fail to load
-PASS restore global state
-Harness: the test ran to completion.
-