Set empty device clip when an image filter has zero bounds

When an image filter has zero input bounds, we should not paint any
contents of it, so we should set an empty clip. This is like the
case that the clip rect doesn't intersect with the image filter's
input bounds.

Bug: chromium:771643
Change-Id: I063c14128dacb83e3572bd2ef4dfeee93c871064
Reviewed-on: https://skia-review.googlesource.com/96943
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Stephen White <senorblanco@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
2 files changed