New SVG turbulence in Skia

This cl contains the code for both CPU and GPU generation of noise. Both
codepaths yield equivalent results.

TEST:Added 'perlinnoise' gm
Review URL: https://codereview.chromium.org/13047005

git-svn-id: http://skia.googlecode.com/svn/trunk/include@8371 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed