Consider homogenizing HTTP/2 Settings prefs.
- SETTINGS_HEADER_TABLE_SIZE depends on the "network.http.spdy.default-hpack-buffer" pref. In Firefox it is set by default to 65536 on desktop and 4096 on mobile.
- SETTINGS_ENABLE_PUSH and SETTINGS_MAX_CONCURRENT_STREAMS depend on "network.http.spdy.allow-push" pref, which is "true" by default.
- SETTINGS_INITIAL_WINDOW_SIZE depends on "network.http.spdy.push-allowance", which is 131072 on desktop and 32768 on mobile by default.
- SETTINGS_MAX_FRAME_SIZE is always set to 0x4000.
The above prefs don't provide significant entropy, unless the user has modified the one or more of them from their default value. Otherwise they mainly serve to distinguish different browsers or platforms.
We could consider making these prefs all the same, to avoid this extra distinction between platforms. But are there performance drawbacks?