This shouldn't be the default because we may want to pause the debugger, but starting profiling automatically (introduced in https://webkit.org/b/157739/) turns off the debugger.
<rdar://problem/26931269>
Created attachment 281797 [details] Proposed Fix
Comment on attachment 281797 [details] Proposed Fix r=me
Committed r202351: <http://trac.webkit.org/changeset/202351>