In bug https://bugs.webkit.org/show_bug.cgi?id=236695 we had to add a few const_cast which isn't particularly elegant. The CachedResource::m_data should be made a const FragmentedSharedBuffer
<rdar://problem/89050403>
Created attachment 452345 [details] Patch for EWS
Created attachment 452494 [details] Patch
Created attachment 452510 [details] Patch
Created attachment 452680 [details] Patch