Update SkiaRenderer+Vulkan pixel test expectation.

6 pixel video tests are now expected to pass on SkiaRenderer Vulkan for
android after some bug fixes. Hence removing them from test expectation.

Bug: 991291
Change-Id: Ifc98a2b674dbd27c3980df6e69b139201eaa58dc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1954258Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Commit-Queue: vikas soni <vikassoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#722651}

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

@@ -182,12 +182,6 @@ crbug.com/974383 [ mac ] Pixel_CanvasDisplayLinearRGBAccelerated2D [ Skip ]
 # Fails when the browser features SkiaRenderer & Vulkan are enabled on Android
 crbug.com/991289 [ android skia-renderer use-vulkan ] Pixel_CSS3DBlueBox [ Skip ]
 crbug.com/991291 [ android android-chromium skia-renderer use-vulkan ] Pixel_Video_Context_Loss_VP9 [ Skip ]
-crbug.com/991291 [ android skia-renderer use-vulkan ] Pixel_Video_MP4 [ Skip ]
-crbug.com/991291 [ android skia-renderer use-vulkan ] Pixel_Video_MP4_FourColors_Aspect_4x3 [ Skip ]
-crbug.com/991291 [ android skia-renderer use-vulkan ] Pixel_Video_MP4_FourColors_Rot_180 [ Skip ]
-crbug.com/991291 [ android skia-renderer use-vulkan ] Pixel_Video_MP4_FourColors_Rot_270 [ Skip ]
-crbug.com/991291 [ android skia-renderer use-vulkan ] Pixel_Video_MP4_FourColors_Rot_90 [ Skip ]
-crbug.com/991291 [ android skia-renderer use-vulkan ] Pixel_Video_VP9 [ Skip ]
 
 # Fails when the browser features SkiaRenderer & GL are enabled on Android.
 # The more specific matching criteria is to prevent collisions with other expectations.