Null check m_mainFrame in WebPageProxy.cpp
Created attachment 369151 [details] Patch
<rdar://problem/47463054>
Comment on attachment 369151 [details] Patch r=me
Comment on attachment 369151 [details] Patch Clearing flags on attachment: 369151 Committed r244970: <https://trac.webkit.org/changeset/244970>
All reviewed patches have been landed. Closing bug.