Mark {virtual/...}/OffscreenCanvas-copyImage.html as flaky

TBR=yiyix@chromium.org

Bug: 1098369
Change-Id: Ia470e911dacc58af8e5d0fbfcba8754d1b3228f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2264809Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781961}

third_party/blink/web_tests/TestExpectations

@@ -183,7 +183,8 @@ crbug.com/774873 [ Mac ] virtual/exotic-color-space/images/color-profile-border-
 crbug.com/774873 [ Linux ] virtual/exotic-color-space/images/color-profile-border-fade.html [ Pass Failure ]
 crbug.com/774873 [ Win ] virtual/exotic-color-space/images/color-profile-border-fade.html [ Pass Failure ]
 
-crbug.com/974652 [ Debug ] fast/canvas/OffscreenCanvas-copyImage.html [ Pass Failure ]
+crbug.com/1098369 fast/canvas/OffscreenCanvas-copyImage.html [ Pass Failure ]
+crbug.com/1098369 virtual/gpu/fast/canvas/OffscreenCanvas-copyImage.html [ Pass Failure ]
 
 crbug.com/1011060 virtual/gpu/fast/canvas/bug382588.html [ Pass Failure ]
 crbug.com/1011060 virtual/gpu/fast/canvas/canvas-lost-gpu-context.html [ Pass Failure Crash ]