api: Flatten and simplify Servo preferences (#34966)

Flatten and simplify Servo's preferences code. In addition, have both
preferences and options passed in as arguments to `Servo::new()` and
make sure not to use the globally set preferences in `servoshell` (as
much as possible now).

Instead of a complex procedural macro to generate preferences, just
expose a very simple derive macro that adds string based getters and
setters.

- All command-line parsing is moved to servoshell.
- There is no longer the concept of a missing preference.
- Preferences no longer have to be part of the resources bundle because
  they now have reasonable default values.
- servoshell specific preferences are no longer part of the preferences
  exposed by the Servo API.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

ports/servoshell/egl/android.rs

@@ -7,7 +7,6 @@
 mod resources;
 mod simpleservo;
 
-use std::collections::HashMap;
 use std::os::raw::{c_char, c_int, c_void};
 use std::sync::Arc;
 
@@ -830,17 +829,6 @@ fn get_options<'local>(
     let native_window =
         unsafe { ANativeWindow_fromSurface(env.get_native_interface(), surface.as_raw()) };
 
-    // FIXME: enable JIT compilation on 32-bit Android after the startup crash issue (#31134) is fixed.
-    let prefs = if cfg!(target_pointer_width = "32") {
-        let mut prefs = HashMap::new();
-        prefs.insert("js.baseline_interpreter.enabled".to_string(), false.into());
-        prefs.insert("js.baseline_jit.enabled".to_string(), false.into());
-        prefs.insert("js.ion.enabled".to_string(), false.into());
-        Some(prefs)
-    } else {
-        None
-    };
-
     let opts = InitOptions {
         args: args.unwrap_or(vec![]),
         url,
@@ -848,7 +836,6 @@ fn get_options<'local>(
         density,
         xr_discovery: None,
         surfman_integration: simpleservo::SurfmanIntegration::Widget(native_window),
-        prefs,
     };
 
     Ok((opts, log, log_str, gst_debug_str))