In the example from the bug we had the filter DAG:
color filter (table)
0: xfermode filter (arith)
0: tile filter [0,80,34,114] -> [0,80,800,480]
0: color filter (table)
0: bitmap src 34x34 -> [0,80,34,114]
1: color filter (table)
0: picture filter [0, 80, 800, 480]
computeFastBounds was coming out of the DAG with a bound of [0,80,34,114] which didn't represent the pixels that would be drawn.
This CL updates SkTileImageFilter to correctly set the bound for the pixels it will hit.
BUG=493783
Review URL: https://codereview.chromium.org/1152553006
05be93bbdf