Enable SurfaceAggregatorPixelTests with Vulkan

Bug: 960795
Change-Id: Icc8c8b8c17dda72966aa1fcad0d326764a768512
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1637400Reviewed-by: Jonathan Ross <jonross@chromium.org>
Commit-Queue: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664748}

components/viz/service/display/surface_aggregator_pixeltest.cc

@@ -62,7 +62,13 @@ class SurfaceAggregatorPixelTest : public cc::RendererPixelTest<RendererType> {
       base::TimeTicks() + base::TimeDelta::FromSeconds(1);
 };
 
-using RendererTypes = ::testing::Types<GLRenderer, SkiaRenderer>;
+using RendererTypes = ::testing::Types<GLRenderer,
+                                       SkiaRenderer
+#ifdef ENABLE_VIZ_VULKAN_TESTS
+                                       ,
+                                       cc::VulkanSkiaRenderer
+#endif
+                                       >;
 TYPED_TEST_SUITE(SurfaceAggregatorPixelTest, RendererTypes);
 
 SharedQuadState* CreateAndAppendTestSharedQuadState(