Remove Pixel_CSSFilterEffects_NoOverlays failure expectation

Test was producing a minor image diff, has been triaged.

Bug: 1040202
Change-Id: Iae6dd08ea4b97d7f4975971b8abbb948d97867d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1992564Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Brandon Jones <bajones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#729597}

content/test/gpu/gpu_tests/test_expectations/pixel_expectations.txt

@@ -199,9 +199,6 @@ crbug.com/1033121 [ android skia-renderer use-gl no-use-vulkan ] Pixel_Video_MP4
 # Produces blank images on Intel HD 630 w/ Mesa 19.0.2
 crbug.com/976861 [ linux intel-0x5912 ] Pixel_OffscreenCanvasTransferToImageBitmap [ Skip ]
 
-# Flakes regularly on Mac.
-crbug.com/1040202 [ mac ] Pixel_CSSFilterEffects_NoOverlays [ Failure ]
-
 # Skip swap chain tests on non-Windows
 [ android ] Pixel_CanvasLowLatency2DSwapChain [ Skip ]
 [ android ] Pixel_CanvasLowLatencyWebGLSwapChain [ Skip ]