Fixing several issues with rendering blurred bitmaps with Ganesh

BUG=http://code.google.com/p/skia/issues/detail?id=305
REVIEW=http://codereview.appspot.com/4630073/



git-svn-id: http://skia.googlecode.com/svn/trunk@1775 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed