Cleanup bitmap/mipmap cache key structs

Use the same pattern (of just including the entire Desc) for both,
rather than manually doing all the same work in the MipMapKey. Remove
the assert about origin when making a desc from a bitmap - this can be
violated when coming in via the MipMap cache, now - and it's handled
correctly in get_bounds_from_bitmap, anyway.

This makes it simpler when I add new fields to the Desc struct.

Bug: skia:
Change-Id: I6b0bfc11a54f3a69a67e8fda7808f116080e61bb
Reviewed-on: https://skia-review.googlesource.com/c/160030
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Auto-Submit: Brian Osman <brianosman@google.com>
1 file changed