Revert "Add experimental API to draw a set of SkImages in one SkCanvas call."

This reverts commit 0a0304c426c44c15897c74dcffb2dcbae544b948.

Reason for revert: Breaking metal

Original change's description:
> Add experimental API to draw a set of SkImages in one SkCanvas call.
> 
> The client provides a src and dst rect for each image as well as
> a bitfield that indicates whether each edge of the image should be
> antialiased. This per-edge AA is useful for tiled compositors.
> 
> Rather than take a full SkPaint this API only takes an alpha, a filter
> quality (which is pinned to kLow), and a blend mode. This is a likely
> point of future evolution.
> 
> Currently the API is only fully implemented for kSrcOver on the GPU
> backend. With other blend modes or on other backends AA will be ignored
> for images that do not have all four edge AA flags set.
> 
> BUG: skia:8444
> 
> Change-Id: I143998dda8ad6a25f64e18cd600392ba553030ac
> Reviewed-on: https://skia-review.googlesource.com/c/159062
> Commit-Queue: Brian Salomon <bsalomon@google.com>
> Reviewed-by: Mike Klein <mtklein@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>

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

Change-Id: I815baaeee5de9c6722cf2b9d071a8e2f7c1b6a96
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/161622
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
43 files changed