Drop redundant code that tries to bump the QoS of the WebContent main thread of UserInteractive when handling a sync IPC. Nowadays, we always run the main thread of the WebContent at UserInteractive QoS (see WTF::Thread::setCurrentThreadIsUserInteractive() call in WebProcess::initializeWebProcess()) so there is no need to boost the QoS during a sync IPC.
Created attachment 414479 [details]
Created attachment 414484 [details]
Committed r269993: <https://trac.webkit.org/changeset/269993>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 414484 [details].