Unclipped selection region should cover start/end position of the selection. Since we exclude hidden text when calculating unclipped selection region, the start/end position can be out of unclipped selection region if it is for hidden text. If that is the case, start/end handle will be invisible. To avoid invisible handle, we take unclipped selection region as reference rectangle in the case.
Created attachment 181977 [details] Patch
Comment on attachment 181977 [details] Patch LGTM.
Comment on attachment 181977 [details] Patch Clearing flags on attachment: 181977 Committed r139295: <http://trac.webkit.org/changeset/139295>
All reviewed patches have been landed. Closing bug.