Update usage of Skia's SkYUVColorSpace enum to allow the addition of a new value

Skia is adding an kIdentity_SkYUVColorSpace enum value to allow explicit postprocessing of a YUV image's components. This CL alters Chromium's handling of the current values to allow the Skia CL to land:

https://skia-review.googlesource.com/c/skia/+/198160 (Add kIdentity_SkYUVColorSpace)

Change-Id: Ie281df8eb9a2cfb1b3bfc921c5e0ef0b30195c03
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1506004
Reviewed-by: Raymes Khoury <raymes@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Reviewed-by: Jonathan Backer <backer@chromium.org>
Commit-Queue: Robert Phillips <robertphillips@google.com>
Cr-Commit-Position: refs/heads/master@{#639123}
2 files changed