Add a IPC::SendSyncOption indicating we should not process incoming IPC while waiting for the sync reply. This can be used in places where we know it would definitely not be safe to re-enter WebCore during a sendSync() call.
Created attachment 332091 [details] WIP Patch
<rdar://problem/21629943>
<rdar://problem/36801024>
Passes all the layout tests locally as well with a syncSync() timeout of infinity. Will add a layout test and reupload. I'll also audit all 3 IPC recipient to validate that they do not do a sync IPC to the WebProcess before responding to the WebProcess' sync IPC.
Created attachment 332177 [details] Patch
Comment on attachment 332177 [details] Patch Clearing flags on attachment: 332177 Committed r227566: <https://trac.webkit.org/changeset/227566>
All reviewed patches have been landed. Closing bug.