Fixed gpu perlin noise on Windows

I just cleaned up and re-ordered some instructions to reduce the number of registers used under the register limit. Instead of looping over channels, the function now only loops over octaves and computes all 4 channels separately within each octave loop. I made a noise function to make it simpler to make the changes and I fixed the code's alignment so that it's more readable.

R=bsalomon@google.com, senorblanco@chromium.org

Review URL: https://codereview.chromium.org/15753005

git-svn-id: http://skia.googlecode.com/svn/trunk@9486 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed