Cleanup restore offsets at end of SkPicture recording

Review URL: http://codereview.appspot.com/6355099/
TEST=skia unit test CanvasTest, test step TwoClipOps
BUG=https://code.google.com/p/chromium/issues/detail?id=133432



git-svn-id: http://skia.googlecode.com/svn/trunk@4577 2bbb7eff-a529-9590-31e7-b0007b416f81
4 files changed