Fix drawSpecialImage

W/o this fix the strict constraint on the specialImage draws can sometimes be removed. This CL ensures that the temporary SkImage always has the actual dimensions of the special Image.

Note: the replacement of full screen clears w/ draws revealed this bug b.c. the image filters were only drawing a rect for the content area of the special images. Thus when the final DAG result was drawn to the canvas some of the bleed through (from the removal of the strict constraint) was showing.

Bug: 755871, 768134
skbug.com/7122

Change-Id: Id67b7143225c24b716e260c973f3bbf68f20188a
Reviewed-on: https://skia-review.googlesource.com/57660
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
5 files changed