virtual/gpu/fast/canvas blending layout tests are slow

NOTRY=true
TBR=fserb@chromium.org

Bug: 866850
Change-Id: I7fdda7adc5c777e2da3cd0ce5cec43016a740a78
Reviewed-on: https://chromium-review.googlesource.com/1153439Reviewed-by: Mohammad Reza Zakerinasab <zakerinasab@chromium.org>
Commit-Queue: Mohammad Reza Zakerinasab <zakerinasab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578705}

third_party/WebKit/LayoutTests/SlowTests

@@ -409,8 +409,12 @@ crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-color-ove
 crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-gradient-over-image.html [ Slow ]
 crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-image-over-gradient.html [ Slow ]
 crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-image-over-image.html [ Slow ]
+crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-image-over-pattern.html [ Slow ]
 crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-pattern-over-color.html [ Slow ]
 crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-pattern-over-gradient.html [ Slow ]
 crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-pattern-over-image.html [ Slow ]
+crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/canvas-blending-pattern-over-pattern.html [ Slow ]
 crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/color-space/canvas-createImageBitmap-p3.html [ Slow ]
-crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/color-space/canvas-createImageBitmap-rec2020.html [ Slow ]
+crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/color-space/canvas-createImageBitmap-rec2020.html [ Slow ]
\ No newline at end of file
+crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/OffscreenCanvas-filter.html [ Slow ]
+crbug.com/866850 [ Linux Mac ] virtual/gpu/fast/canvas/OffscreenCanvas-filter-in-worker.html [ Slow ]