Allow setting userscripts directly without the need of files (#35388)

* Allow settings userscripts through preferences

Signed-off-by: Tony <legendmastertony@gmail.com>

* mach fmt instead of cargo fmt

Signed-off-by: Tony <legendmastertony@gmail.com>

* Fix pref loading not working for array values

Signed-off-by: Tony <legendmastertony@gmail.com>

* Use pref! in userscripts instead

Signed-off-by: Tony <legendmastertony@gmail.com>

* Implement the model jdm suggested
- Remove userscripts from all places and move it to servoshell
- Add in `UserContentManager` struct and passing it through `Servo::new`
all the way down to script thread

Signed-off-by: Tony <legendmastertony@gmail.com>

* Apply suggestions from code review and format

Signed-off-by: Tony <legendmastertony@gmail.com>

* Revert unrelated change

Signed-off-by: Tony <legendmastertony@gmail.com>

---------

Signed-off-by: Tony <legendmastertony@gmail.com>
Signed-off-by: Tony <68118705+Legend-Master@users.noreply.github.com>

ports/servoshell/desktop/app.rs

@@ -6,6 +6,7 @@
 
 use std::cell::Cell;
 use std::collections::HashMap;
+use std::path::Path;
 use std::rc::Rc;
 use std::time::Instant;
 use std::{env, fs};
@@ -16,6 +17,7 @@ use servo::config::opts::Opts;
 use servo::config::prefs::Preferences;
 use servo::servo_config::pref;
 use servo::servo_url::ServoUrl;
+use servo::user_content_manager::{UserContentManager, UserScript};
 use servo::webxr::glwindow::GlWindowDiscovery;
 #[cfg(target_os = "windows")]
 use servo::webxr::openxr::{AppInfo, OpenXrDiscovery};
@@ -146,6 +148,13 @@ impl App {
             }
         }
 
+        let mut user_content_manager = UserContentManager::new();
+        for script in load_userscripts(self.servoshell_preferences.userscripts_directory.as_deref())
+            .expect("Loading userscripts failed")
+        {
+            user_content_manager.add_script(script);
+        }
+
         let servo = Servo::new(
             self.opts.clone(),
             self.preferences.clone(),
@@ -153,6 +162,7 @@ impl App {
             embedder,
             Rc::new(UpcastedWindow(window.clone())),
             self.servoshell_preferences.user_agent.clone(),
+            user_content_manager,
         );
         servo.setup_logging();
 
@@ -442,3 +452,20 @@ impl ApplicationHandler<WakerEvent> for App {
         self.suspended.set(true);
     }
 }
+
+fn load_userscripts(userscripts_directory: Option<&Path>) -> std::io::Result<Vec<UserScript>> {
+    let mut userscripts = Vec::new();
+    if let Some(userscripts_directory) = &userscripts_directory {
+        let mut files = std::fs::read_dir(userscripts_directory)?
+            .map(|e| e.map(|entry| entry.path()))
+            .collect::<Result<Vec<_>, _>>()?;
+        files.sort();
+        for file in files {
+            userscripts.push(UserScript {
+                script: std::fs::read_to_string(&file)?,
+                source_file: Some(file),
+            });
+        }
+    }
+    Ok(userscripts)
+}

ports/servoshell/egl/android/simpleservo.rs

@@ -99,6 +99,7 @@ pub fn init(
         embedder_callbacks,
         window_callbacks.clone(),
         None,
+        Default::default(),
     );
 
     APP.with(|app| {

ports/servoshell/egl/ohos/simpleservo.rs

@@ -131,6 +131,7 @@ pub fn init(
         embedder_callbacks,
         window_callbacks.clone(),
         None, /* user_agent */
+        Default::default(),
     );
 
     let app_state = RunningAppState::new(

ports/servoshell/prefs.rs

@@ -56,6 +56,9 @@ pub(crate) struct ServoShellPreferences {
     pub output_image_path: Option<String>,
     /// Whether or not to exit after Servo detects a stable output image in all WebViews.
     pub exit_after_stable_image: bool,
+    /// Where to load userscripts from, if any.
+    /// and if the option isn't passed userscripts won't be loaded.
+    pub userscripts_directory: Option<PathBuf>,
 }
 
 impl Default for ServoShellPreferences {
@@ -74,6 +77,7 @@ impl Default for ServoShellPreferences {
             user_agent: None,
             output_image_path: None,
             exit_after_stable_image: false,
+            userscripts_directory: None,
         }
     }
 }
@@ -622,6 +626,9 @@ pub(crate) fn parse_command_line_arguments(args: Vec<String>) -> ArgumentParsing
         screen_size_override,
         output_image_path,
         exit_after_stable_image: exit_after_load,
+        userscripts_directory: opt_match
+            .opt_default("userscripts", "resources/user-agent-js")
+            .map(PathBuf::from),
         ..Default::default()
     };
 
@@ -636,7 +643,6 @@ pub(crate) fn parse_command_line_arguments(args: Vec<String>) -> ArgumentParsing
         time_profiling,
         time_profiler_trace_path: opt_match.opt_str("profiler-trace-path"),
         nonincremental_layout,
-        userscripts: opt_match.opt_default("userscripts", "resources/user-agent-js"),
         user_stylesheets,
         hard_fail: opt_match.opt_present("f") && !opt_match.opt_present("F"),
         webdriver_port,