existing obj->safeRef(), which is unsafe since it can its 'if (this)' can be optimized away by some compilers. fix some overflows in mimpmap generation git-svn-id: http://skia.googlecode.com/svn/trunk@181 2bbb7eff-a529-9590-31e7-b0007b416f81
git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81