SkColorPrimaries: Add mojo support

Add an explicit SkColorPrimaries member to gfx::DisplayColorSpaces.
This is needed because the color gamut of the output device is
independent of the color space in which content is rendered (e.g, on
Windows, we have a fixed menu of color spaces to render to).

Add mojo support for SkColorPrimaries to allow communicating it from
the browser to the renderer and GPU processes. In future patches, we
will sent SkColorPrimaries from the GPU process to the browser (e.g,
on Windows, where this information originates in DXGI_OUTPUT_DESC1).

Bug: 1274220
Change-Id: Ic905fd402dde099730f81a63f23cf907d83358ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3868744
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: ccameron chromium <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1044483}