Include color type and color space in bitmap cache key

Lazy images will soon support decoding to multiple color types and
color spaces. To avoid cache collisions, we need to fold the decoded
color type and color space into the key.

To avoid storing multiple (different) bitmaps with the same gen ID,
stop propagating the image's ID to the one allocated in the cache.

Bug: skia:
Change-Id: I06714725d4309ec813b75e42cc76eda2cda3d2e0
Reviewed-on: https://skia-review.googlesource.com/c/160380
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
7 files changed