media/base/VideoPixelFormat: Add XBGR and ABGR

VideoPixelFormat doesn't have values for XBGR and ABGR, even though it has ones
for ARGB, XRGB, RGB and RGBA. This adds XBGR and ABGR so that all sorts of RGBA
formats are in VideoPixelFormat.
They are not used on Chrome stack. On the other hand, in ARC++, Android
container can pass XBGR and ABGR formatted buffer. Those values are thus needed.

TEST=./media_unittests on Linux

Change-Id: I03fda9a9afa9ae1d5dfa7af873898665f9ac2d9d
Reviewed-by: Fredrik Hubinette <>
Reviewed-by: Daniel Cheng <>
Commit-Queue: Hirokazu Honda <>
Cr-Commit-Position: refs/heads/master@{#603414}
12 files changed