Add a new bench that tests a simple image filter DAG.

This bench exercises a blur filter connected to 5 inputs of the same
merge filter.

R=junov@chromium.org

Review URL: https://codereview.chromium.org/233383002

git-svn-id: http://skia.googlecode.com/svn/trunk/gyp@14135 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed