The layout of the navigation bar can often cause the last button to overflow. This is due to offsetWidth returning a rounded up value in with subpixel layout. We need to use getBoundingClientRect() so we don't accumulate the rounding as we add widths together during our layout functions.
<rdar://problem/20743712>
Created attachment 251947 [details] Patch
Comment on attachment 251947 [details] Patch r=me There might be better / more descriptive names. Maybe subpixelOffsetWidth, preciseOffsetWidth?
Comment on attachment 251947 [details] Patch Clearing flags on attachment: 251947 Committed r183565: <http://trac.webkit.org/changeset/183565>
All reviewed patches have been landed. Closing bug.