gpu: Allow RasterCommandBufferStub to initialize on Fuchsia

This removes a NOTIMPLEMENTED() in RasterCommandBufferStub::Initialize()
so that we can use that code on Fuchsia.

Bug: 861853
Test: run_content_shell --ozone-platform=scenic --disable-gpu --enable-vulkan
Change-Id: Iadc55361d19165ecb6129675c8d569406484bd2f
Reviewed-on: https://chromium-review.googlesource.com/c/1343239
Commit-Queue: Michael Spang <spang@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609446}
1 file changed