add rowBytes param to setPreLock, in prep for onNewLockPixels change

need _win.cc change from https://codereview.chromium.org/124503002/ when this lands in chrome

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/125063002

git-svn-id: http://skia.googlecode.com/svn/trunk@12907 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed