Web Inspector: capture and replay stopLoading() and stopLoadingFrame() commands that come from WebKit2 embedders.
Web Replay: Rename Input{Encoder, Decoder} to {Encoder, Decoder}Context.
Web Replay: Refactor input serialization to not be stack-based. Instead,
explicit encoding contexts (lists or maps) are used.
Web Replay: move recording memory size summation code to ReplayRecording.