Implement crop rect support for the merge image filter.

Note: this will require rebaselining of the imagefilterscropped and testimagefilters GMs.

R=reed@google.com

Review URL: https://codereview.chromium.org/23600047

git-svn-id: http://skia.googlecode.com/svn/trunk/src@11387 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed