Revert "conformance/rendering/multisample-corruption.html flaky in WebGL1 and 2"

This reverts commit accbbb4f.

Reason for revert: fixed in crrev.com/819493

Original change's description:
> conformance/rendering/multisample-corruption.html flaky in WebGL1 and 2
>
> TBR=kbr
>
> Bug: 1004581
> Change-Id: I027e384cea1233e7fcc948d7989c22b286d7b381
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2473160
> Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
> Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#817321}

TBR=ynovikov@chromium.org,kbr@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1004581
Change-Id: Ibea2b7e4ed6c9f88ab21f58518ca3685046d828b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2491002Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819711}

content/test/gpu/gpu_tests/test_expectations/webgl2_conformance_expectations.txt

@@ -163,11 +163,6 @@ crbug.com/798117 [ angle-vulkan win nvidia ] conformance/glsl/bugs/assign-to-swi
 crbug.com/798117 [ linux nvidia ] conformance/glsl/bugs/assign-to-swizzled-twice-in-function.html [ Failure ]
 crbug.com/792210 [ nvidia ] conformance/glsl/bugs/in-parameter-passed-as-inout-argument-and-global.html [ Failure ]
 
-# Fails everywhere
-crbug.com/1004581 [ win ] conformance/rendering/multisample-corruption.html [ RetryOnFailure ]
-crbug.com/1004581 [ linux ] conformance/rendering/multisample-corruption.html [ RetryOnFailure ]
-crbug.com/1004581 [ mac ] conformance/rendering/multisample-corruption.html [ RetryOnFailure ]
-
 ####################
 # Win failures     #
 ####################

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

@@ -163,10 +163,6 @@ crbug.com/1082533 [ mac intel ] conformance/textures/misc/texture-copying-and-de
 crbug.com/1018028 [ win angle-vulkan nvidia ] conformance/rendering/bind-framebuffer-flush-bug.html [ Failure ]
 crbug.com/1110111 [ win nvidia ] conformance/rendering/point-no-attributes.html [ RetryOnFailure ]
 
-crbug.com/1004581 [ win ] conformance/rendering/multisample-corruption.html [ RetryOnFailure ]
-crbug.com/1004581 [ linux ] conformance/rendering/multisample-corruption.html [ RetryOnFailure ]
-crbug.com/1004581 [ mac ] conformance/rendering/multisample-corruption.html [ RetryOnFailure ]
-
 # Skipping new tests
 crbug.com/angleproject/5038 conformance/extensions/ext-color-buffer-half-float.html [ Skip ]
 
@@ -394,6 +390,7 @@ crbug.com/angleproject/2926 [ win amd angle-vulkan passthrough ] deqp/data/gles2
 crbug.com/angleproject/2926 [ win amd angle-vulkan passthrough ] deqp/data/gles2/shaders/linkage.html [ Failure ]
 crbug.com/974347 [ win amd angle-vulkan passthrough ] conformance/textures/image/tex-2d-luminance-luminance-unsigned_byte.html [ Failure ]
 crbug.com/974347 [ win amd angle-vulkan passthrough ] conformance/textures/image/tex-2d-luminance_alpha-luminance_alpha-unsigned_byte.html [ Failure ]
+crbug.com/1004581 [ win amd angle-vulkan passthrough ] conformance/rendering/multisample-corruption.html [ Failure ]
 crbug.com/1010942 [ win amd angle-vulkan passthrough ] conformance/glsl/samplers/glsl-function-texture2dproj.html [ Failure ]
 crbug.com/angleproject/4286 [ win amd angle-vulkan passthrough ] conformance/rendering/out-of-bounds-array-buffers.html [ Failure ]