Enable BackdropFilterBlurOffAxis/SkiaDawn

This test is now passing again. A skia change was rolled in that had
depended on a spirv-cross change, which has now also been rolled in.

Bug: 1126617
Change-Id: I86c9de10732cc39d7860cbc982186f5695a7e112
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2412888
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Auto-Submit: Sean Gilhuly <sgilhuly@chromium.org>
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807905}

cc/trees/layer_tree_host_pixeltest_filters.cc

@@ -360,11 +360,9 @@ class LayerTreeHostBlurFiltersPixelTestGPULayerList
   }
 };
 
-// TODO(sgilhuly): Enable these tests for Skia Dawn, and switch over to using
-// viz::GetGpuRendererTypes().
 INSTANTIATE_TEST_SUITE_P(PixelResourceTest,
                          LayerTreeHostBlurFiltersPixelTestGPULayerList,
-                         ::testing::ValuesIn(viz::GetGpuRendererTypesNoDawn()),
+                         ::testing::ValuesIn(viz::GetGpuRendererTypes()),
                          ::testing::PrintToStringParamName());
 
 TEST_P(LayerTreeHostBlurFiltersPixelTestGPULayerList,