Revert "Include color type and color space in bitmap cache key"

This reverts commit 274a89e0f5f863cbc41e4313b328db9c2905ea18.

Reason for revert: Failing unit tests

Original change's description:
> 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>

TBR=mtklein@google.com,brianosman@google.com,reed@google.com

Change-Id: I6c5834b5b65b85dbb7661f526920d9a140ba5737
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/c/160801
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
7 files changed