Fixed double offset in resize filter

The fix is trivial, simply remove the extra offset

I added another case to the resizeimagefilter gm and made it so that it looks exactly like the one next to it, so that failure is easy to detect visually.

BUG=skia:
R=senorblanco@google.com, senorblanco@chromium.org

Author: sugoi@chromium.org

Review URL: https://codereview.chromium.org/208303002

git-svn-id: http://skia.googlecode.com/svn/trunk@13892 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed