1. Take 1 heap snapshot, wait for the summary view to open. 2. Take another heap snapshot, wait for the summary view to open. 3. Select "Comparison" view. Result: Nothing happens. Note that after frontend reopening if you open the second snapshot and select "Comparison" view the diff will show up.
This is a regression after http://trac.webkit.org/changeset/116218 (early return from WebInspector.HeapProfileHeader.prototype.load)
Created attachment 141184 [details] Patch
Comment on attachment 141184 [details] Patch Clearing flags on attachment: 141184 Committed r116681: <http://trac.webkit.org/changeset/116681>
All reviewed patches have been landed. Closing bug.