SwiftShader Vulkan blink_web_tests

Creates vulkan_swift_shader_blink_web_tests

This adds a variant of blink_web_tests to the Chrome-GPU
FYI bot: "Linux FYI SkiaRenderer Vulkan (NVIDIA)"

This will allow us to get correctness coverage of
SkiaRenderer+Vulkan until we have bots setup that can run
the native Vulkan.

This change adds a new FlagExpectations file to represent
the failures occurring with Vulkan, which pass with GL.
While also updating the skia_renderer_blink_web_tests to
properly respect the SKIP expectation.

Documentation on FlagExpectations has been updated to
reflect how to mix expectations with test lists, while
actually skipping tests.

TEST=vulkan_swift_shader_blink_web_tests

Bug: 969824
Change-Id: I8dec7f9e1c921868b2216efb0bd63ea952fc6dc4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1652791
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Reviewed-by: Jonathan Backer <backer@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672138}
5 files changed