change setLength and Normalize to handle when mag2 overflows a float, but the
actual lenght does not.

R=caryclark@google.com

Review URL: https://codereview.chromium.org/14838006

git-svn-id: http://skia.googlecode.com/svn/trunk@8988 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed