Remove DMSrcSinkAndroid.

This code involves Skia having knowledge of HWUI internals and
causes problems with various build systems.  It is also not
currently being used and is therefore expendable.

Change-Id: I7b6a37fa4c9afcefbc6a957b49e7735da872ff14
Merged-In: I7b6a37fa4c9afcefbc6a957b49e7735da872ff14
Reviewed-on: https://skia-review.googlesource.com/6597
Commit-Queue: Derek Sollenberger <djsollen@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
(cherry picked from commit c65386ae55555819e321b77fd5a2b25dfcf94c3d)
6 files changed