The first window now loads its document the moment Electron is ready:
the same index.html without its module scripts, plus a sanitized copy of
the shell captured at the end of the previous run. The renderer process,
the stylesheet and the fonts are ready while the main bundle and the
layers load, and the scripts are added when the window is adopted.
The renderer asks for its RPC MessagePort instead of receiving one on
did-finish-load, since that event fires before the scripts exist.
The startup splash and its 300 ms fade are skipped when a snapshot is
present; the snapshot is removed when the interface would have been
revealed, and re-captured once idle and after route changes.
LukeParkerDev
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