get rid of VideoFrameMetadata::COLOR_SPACE

It's been deprecated for a while, this CL finally gets rid of it.

Bug: 754986
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Icc06af298f2e46252b2bc3e7ac73b25c66f3fd26
Reviewed-on: https://chromium-review.googlesource.com/1235209
Reviewed-by: Yuri Wiitala <miu@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Fredrik Hubinette <hubbe@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593297}
7 files changed