Time distribution across script event categories.

components/script/dom/dedicatedworkerglobalscope.rs

@@ -17,9 +17,10 @@ use dom::bindings::structuredclone::StructuredCloneData;
 use dom::bindings::utils::Reflectable;
 use dom::eventtarget::{EventTarget, EventTargetTypeId};
 use dom::messageevent::MessageEvent;
-use dom::worker::{TrustedWorkerAddress, WorkerMessageHandler, WorkerEventHandler};
+use dom::worker::{TrustedWorkerAddress, WorkerMessageHandler, SimpleWorkerErrorHandler};
 use dom::workerglobalscope::WorkerGlobalScope;
 use dom::workerglobalscope::{WorkerGlobalScopeTypeId, WorkerGlobalScopeInit};
+use script_task::ScriptTaskEventCategory::WorkerEvent;
 use script_task::{ScriptTask, ScriptChan, TimerSource, ScriptPort, StackRootTLS, CommonScriptMsg};
 
 use devtools_traits::DevtoolScriptControlMsg;
@@ -207,8 +208,8 @@ impl DedicatedWorkerGlobalScope {
             let (url, source) = match load_whole_resource(&init.resource_task, worker_url) {
                 Err(_) => {
                     println!("error loading script {}", serialized_worker_url);
-                    parent_sender.send(CommonScriptMsg::RunnableMsg(
+                    parent_sender.send(CommonScriptMsg::RunnableMsg(WorkerEvent,
-                        box WorkerEventHandler::new(worker))).unwrap();
+                        box SimpleWorkerErrorHandler::new(worker))).unwrap();
                     return;
                 }
                 Ok((metadata, bytes)) => {
@@ -308,7 +309,7 @@ impl DedicatedWorkerGlobalScope {
                 data.read(GlobalRef::Worker(scope), message.handle_mut());
                 MessageEvent::dispatch_jsval(target, GlobalRef::Worker(scope), message.handle());
             },
-            WorkerScriptMsg::Common(CommonScriptMsg::RunnableMsg(runnable)) => {
+            WorkerScriptMsg::Common(CommonScriptMsg::RunnableMsg(_, runnable)) => {
                 runnable.handler()
             },
             WorkerScriptMsg::Common(CommonScriptMsg::RefcountCleanup(addr)) => {
@@ -359,7 +360,7 @@ impl DedicatedWorkerGlobalScopeMethods for DedicatedWorkerGlobalScope {
     fn PostMessage(&self, cx: *mut JSContext, message: HandleValue) -> ErrorResult {
         let data = try!(StructuredCloneData::write(cx, message));
         let worker = self.worker.borrow().as_ref().unwrap().clone();
-        self.parent_sender.send(CommonScriptMsg::RunnableMsg(
+        self.parent_sender.send(CommonScriptMsg::RunnableMsg(WorkerEvent,
             box WorkerMessageHandler::new(worker, data))).unwrap();
         Ok(())
     }

components/script/dom/filereader.rs

@@ -22,6 +22,7 @@ use encoding::label::encoding_from_whatwg_label;
 use encoding::types::{EncodingRef, DecoderTrap};
 use hyper::mime::{Mime, Attr};
 use rustc_serialize::base64::{Config, ToBase64, CharacterSet, Newline};
+use script_task::ScriptTaskEventCategory::FileRead;
 use script_task::{ScriptChan, Runnable, ScriptPort, CommonScriptMsg};
 use std::cell::{Cell, RefCell};
 use std::sync::mpsc;
@@ -401,22 +402,22 @@ fn perform_annotated_read_operation(gen_id: GenerationId, data: ReadMetaData, bl
     let chan = &script_chan;
     // Step 4
     let task = box FileReaderEvent::ProcessRead(filereader.clone(), gen_id);
-    chan.send(CommonScriptMsg::RunnableMsg(task)).unwrap();
+    chan.send(CommonScriptMsg::RunnableMsg(FileRead, task)).unwrap();
 
     let task = box FileReaderEvent::ProcessReadData(filereader.clone(),
         gen_id, DOMString::new());
-    chan.send(CommonScriptMsg::RunnableMsg(task)).unwrap();
+    chan.send(CommonScriptMsg::RunnableMsg(FileRead, task)).unwrap();
 
     let bytes = match blob_contents.recv() {
         Ok(bytes) => bytes,
         Err(_) => {
             let task = box FileReaderEvent::ProcessReadError(filereader,
                 gen_id, DOMErrorName::NotFoundError);
-            chan.send(CommonScriptMsg::RunnableMsg(task)).unwrap();
+            chan.send(CommonScriptMsg::RunnableMsg(FileRead, task)).unwrap();
             return;
         }
     };
 
     let task = box FileReaderEvent::ProcessReadEOF(filereader, gen_id, data, bytes);
-    chan.send(CommonScriptMsg::RunnableMsg(task)).unwrap();
+    chan.send(CommonScriptMsg::RunnableMsg(FileRead, task)).unwrap();
 }

components/script/dom/htmlimageelement.rs

@@ -21,6 +21,7 @@ use dom::eventtarget::{EventTarget, EventTargetTypeId};
 use dom::htmlelement::{HTMLElement, HTMLElementTypeId};
 use dom::node::{document_from_node, Node, NodeTypeId, NodeDamage, window_from_node};
 use dom::virtualmethods::VirtualMethods;
+use script_task::ScriptTaskEventCategory::UpdateReplacedElement;
 use script_task::{Runnable, ScriptChan, CommonScriptMsg};
 use string_cache::Atom;
 use util::str::DOMString;
@@ -131,7 +132,7 @@ impl HTMLImageElement {
                     // Return the image via a message to the script task, which marks the element
                     // as dirty and triggers a reflow.
                     let image_response = message.to().unwrap();
-                    script_chan.send(CommonScriptMsg::RunnableMsg(
+                    script_chan.send(CommonScriptMsg::RunnableMsg(UpdateReplacedElement,
                         box ImageResponseHandlerRunnable::new(
                             trusted_node.clone(), image_response))).unwrap();
                 });

components/script/dom/htmlscriptelement.rs

@@ -32,6 +32,7 @@ use dom::window::ScriptHelpers;
 use js::jsapi::RootedValue;
 use js::jsval::UndefinedValue;
 use network_listener::{NetworkListener, PreInvoke};
+use script_task::ScriptTaskEventCategory::ScriptEvent;
 use script_task::{ScriptChan, Runnable, CommonScriptMsg};
 
 use encoding::all::UTF_8;
@@ -426,7 +427,7 @@ impl HTMLScriptElement {
                 element: handler,
                 is_error: false,
             };
-            chan.send(CommonScriptMsg::RunnableMsg(dispatcher)).unwrap();
+            chan.send(CommonScriptMsg::RunnableMsg(ScriptEvent, dispatcher)).unwrap();
         }
     }
 
@@ -439,7 +440,7 @@ impl HTMLScriptElement {
             element: handler,
             is_error: true,
         };
-        chan.send(CommonScriptMsg::RunnableMsg(dispatcher)).unwrap();
+        chan.send(CommonScriptMsg::RunnableMsg(ScriptEvent, dispatcher)).unwrap();
     }
 
     pub fn dispatch_before_script_execute_event(&self) -> bool {

components/script/dom/htmltextareaelement.rs

@@ -25,6 +25,7 @@ use dom::node::{ChildrenMutation, Node, NodeDamage};
 use dom::node::{NodeTypeId, document_from_node, window_from_node};
 use dom::virtualmethods::VirtualMethods;
 use msg::constellation_msg::ConstellationChan;
+use script_task::ScriptTaskEventCategory::InputEvent;
 use script_task::{Runnable, CommonScriptMsg};
 use textinput::{TextInput, Lines, KeyReaction};
 
@@ -356,7 +357,7 @@ impl VirtualMethods for HTMLTextAreaElement {
                             let dispatcher = ChangeEventRunnable {
                                 element: handler,
                             };
-                            let _ = chan.send(CommonScriptMsg::RunnableMsg(box dispatcher));
+                            let _ = chan.send(CommonScriptMsg::RunnableMsg(InputEvent, box dispatcher));
                         }
 
                         self.force_relayout();

components/script/dom/websocket.rs

@@ -22,6 +22,7 @@ use dom::closeevent::CloseEvent;
 use dom::event::{Event, EventBubbles, EventCancelable};
 use dom::eventtarget::{EventTarget, EventTargetTypeId};
 use dom::messageevent::MessageEvent;
+use script_task::ScriptTaskEventCategory::WebSocketEvent;
 use script_task::{Runnable, CommonScriptMsg};
 
 use net_traits::hosts::replace_hosts;
@@ -182,7 +183,7 @@ impl WebSocket {
                     let task = box CloseTask {
                         addr: address,
                     };
-                    sender.send(CommonScriptMsg::RunnableMsg(task)).unwrap();
+                    sender.send(CommonScriptMsg::RunnableMsg(WebSocketEvent, task)).unwrap();
                     return;
                 }
             };
@@ -192,7 +193,7 @@ impl WebSocket {
                 addr: address.clone(),
                 sender: ws_sender.clone(),
             };
-            sender.send(CommonScriptMsg::RunnableMsg(open_task)).unwrap();
+            sender.send(CommonScriptMsg::RunnableMsg(WebSocketEvent, open_task)).unwrap();
 
             for message in receiver.incoming_messages() {
                 let message = match message {
@@ -208,7 +209,7 @@ impl WebSocket {
                         let task = box CloseTask {
                             addr: address,
                         };
-                        sender.send(CommonScriptMsg::RunnableMsg(task)).unwrap();
+                        sender.send(CommonScriptMsg::RunnableMsg(WebSocketEvent, task)).unwrap();
                         break;
                     },
                     Err(_) => break,
@@ -217,7 +218,7 @@ impl WebSocket {
                     address: address.clone(),
                     message: message,
                 };
-                sender.send(CommonScriptMsg::RunnableMsg(message_task)).unwrap();
+                sender.send(CommonScriptMsg::RunnableMsg(WebSocketEvent, message_task)).unwrap();
             }
         });
 

components/script/dom/worker.rs

@@ -186,20 +186,20 @@ impl Runnable for WorkerMessageHandler {
     }
 }
 
-pub struct WorkerEventHandler {
+pub struct SimpleWorkerErrorHandler {
     addr: TrustedWorkerAddress,
 }
 
-impl WorkerEventHandler {
+impl SimpleWorkerErrorHandler {
-    pub fn new(addr: TrustedWorkerAddress) -> WorkerEventHandler {
+    pub fn new(addr: TrustedWorkerAddress) -> SimpleWorkerErrorHandler {
-        WorkerEventHandler {
+        SimpleWorkerErrorHandler {
             addr: addr
         }
     }
 }
 
-impl Runnable for WorkerEventHandler {
+impl Runnable for SimpleWorkerErrorHandler {
-    fn handler(self: Box<WorkerEventHandler>) {
+    fn handler(self: Box<SimpleWorkerErrorHandler>) {
         let this = *self;
         Worker::dispatch_simple_error(this.addr);
     }

components/script/dom/xmlhttprequest.rs

@@ -27,6 +27,7 @@ use dom::xmlhttprequesteventtarget::XMLHttpRequestEventTarget;
 use dom::xmlhttprequesteventtarget::XMLHttpRequestEventTargetTypeId;
 use dom::xmlhttprequestupload::XMLHttpRequestUpload;
 use network_listener::{NetworkListener, PreInvoke};
+use script_task::ScriptTaskEventCategory::XhrEvent;
 use script_task::{ScriptChan, Runnable, ScriptPort, CommonScriptMsg};
 
 use encoding::all::UTF_8;
@@ -989,7 +990,7 @@ impl XMLHttpRequest {
             sleep_ms(duration_ms);
             match cancel_rx.try_recv() {
                 Err(TryRecvError::Empty) => {
-                    timeout_target.send(CommonScriptMsg::RunnableMsg(box XHRTimeout {
+                    timeout_target.send(CommonScriptMsg::RunnableMsg(XhrEvent, box XHRTimeout {
                         xhr: xhr,
                         gen_id: gen_id,
                     })).unwrap();

components/script/network_listener.rs

@@ -3,6 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use net_traits::{AsyncResponseListener, ResponseAction};
+use script_task::ScriptTaskEventCategory::NetworkEvent;
 use script_task::{ScriptChan, Runnable, CommonScriptMsg};
 use std::sync::{Arc, Mutex};
 
@@ -15,7 +16,7 @@ pub struct NetworkListener<T: AsyncResponseListener + PreInvoke + Send + 'static
 
 impl<T: AsyncResponseListener + PreInvoke + Send + 'static> NetworkListener<T> {
     pub fn notify(&self, action: ResponseAction) {
-        if let Err(err) = self.script_chan.send(CommonScriptMsg::RunnableMsg(box ListenerRunnable {
+        if let Err(err) = self.script_chan.send(CommonScriptMsg::RunnableMsg(NetworkEvent, box ListenerRunnable {
             context: self.context.clone(),
             action: action,
         })) {

components/script/script_task.rs

@@ -94,11 +94,12 @@ use js::jsval::UndefinedValue;
 use js::rust::Runtime;
 use url::{Url, UrlParser};
 
+use core::ops::Deref;
 use libc;
 use std::any::Any;
 use std::borrow::ToOwned;
 use std::cell::{Cell, RefCell};
-use std::collections::HashSet;
+use std::collections::{HashMap, HashSet};
 use std::io::{stdout, Write};
 use std::mem as std_mem;
 use std::option::Option;
@@ -178,6 +179,13 @@ pub trait MainThreadRunnable {
     fn handler(self: Box<Self>, script_task: &ScriptTask);
 }
 
+enum MixedMessage {
+    FromConstellation(ConstellationControlMsg),
+    FromScript(MainThreadScriptMsg),
+    FromDevtools(DevtoolScriptControlMsg),
+    FromImageCache(ImageCacheResult),
+}
+
 /// Common messages used to control the event loops in both the script and the worker
 pub enum CommonScriptMsg {
     /// Requests that the script task measure its memory usage. The results are sent back via the
@@ -190,7 +198,27 @@ pub enum CommonScriptMsg {
     /// A DOM object's last pinned reference was removed (dispatched to all tasks).
     RefcountCleanup(TrustedReference),
     /// Generic message that encapsulates event handling.
-    RunnableMsg(Box<Runnable + Send>),
+    RunnableMsg(ScriptTaskEventCategory, Box<Runnable + Send>),
+}
+
+#[derive(Clone, Copy, Debug, Eq, Hash, JSTraceable, PartialEq)]
+pub enum ScriptTaskEventCategory {
+    AttachLayout,
+    ConstellationMsg,
+    DevtoolsMsg,
+    DocumentEvent,
+    DomEvent,
+    FileRead,
+    ImageCacheMsg,
+    InputEvent,
+    NetworkEvent,
+    Resize,
+    ScriptEvent,
+    UpdateReplacedElement,
+    SetViewport,
+    WebSocketEvent,
+    WorkerEvent,
+    XhrEvent,
 }
 
 /// Messages used to control the script event loop
@@ -390,6 +418,11 @@ pub struct ScriptTask {
 
     /// List of pipelines that have been owned and closed by this script task.
     closed_pipelines: RefCell<HashSet<PipelineId>>,
+
+    /// When profiling data should be written out to stdout.
+    perf_profiler_next_report: Cell<Option<u64>>,
+    /// How much time was spent on what since the last report.
+    perf_profiler_times: RefCell<HashMap<ScriptTaskEventCategory, u64>>,
 }
 
 /// In the event of task failure, all data on the stack runs its destructor. However, there
@@ -635,6 +668,9 @@ impl ScriptTask {
             js_runtime: Rc::new(runtime),
             mouse_over_targets: DOMRefCell::new(vec!()),
             closed_pipelines: RefCell::new(HashSet::new()),
+
+            perf_profiler_next_report: Cell::new(None),
+            perf_profiler_times: RefCell::new(HashMap::new()),
         }
     }
 
@@ -713,13 +749,6 @@ impl ScriptTask {
             self.handle_event(id, ResizeEvent(size));
         }
 
-        enum MixedMessage {
-            FromConstellation(ConstellationControlMsg),
-            FromScript(MainThreadScriptMsg),
-            FromDevtools(DevtoolScriptControlMsg),
-            FromImageCache(ImageCacheResult),
-        }
-
         // Store new resizes, and gather all other events.
         let mut sequential = vec!();
 
@@ -762,13 +791,19 @@ impl ScriptTask {
                 // child list yet, causing the find() to fail.
                 MixedMessage::FromConstellation(ConstellationControlMsg::AttachLayout(
                         new_layout_info)) => {
+                    self.profile_event(ScriptTaskEventCategory::AttachLayout, || {
                         self.handle_new_layout(new_layout_info);
+                    })
                 }
                 MixedMessage::FromConstellation(ConstellationControlMsg::Resize(id, size)) => {
+                    self.profile_event(ScriptTaskEventCategory::Resize, || {
                         self.handle_resize(id, size);
+                    })
                 }
                 MixedMessage::FromConstellation(ConstellationControlMsg::Viewport(id, rect)) => {
+                    self.profile_event(ScriptTaskEventCategory::SetViewport, || {
                         self.handle_viewport(id, rect);
+                    })
                 }
                 MixedMessage::FromConstellation(ConstellationControlMsg::TickAllAnimations(
                         pipeline_id)) => {
@@ -815,10 +850,13 @@ impl ScriptTask {
 
         // Process the gathered events.
         for msg in sequential {
+            let category = self.categorize_msg(&msg);
+
+            let result = self.profile_event(category, move || {
                 match msg {
                     MixedMessage::FromConstellation(ConstellationControlMsg::ExitPipeline(id, exit_type)) => {
                         if self.handle_exit_pipeline_msg(id, exit_type) {
-                        return false
+                            return Some(false)
                         }
                     },
                     MixedMessage::FromConstellation(inner_msg) => self.handle_msg_from_constellation(inner_msg),
@@ -826,6 +864,13 @@ impl ScriptTask {
                     MixedMessage::FromDevtools(inner_msg) => self.handle_msg_from_devtools(inner_msg),
                     MixedMessage::FromImageCache(inner_msg) => self.handle_msg_from_image_cache(inner_msg),
                 }
+
+                None
+            });
+
+            if let Some(retval) = result {
+                return retval
+            }
         }
 
         // Issue batched reflows on any pages that require it (e.g. if images loaded)
@@ -847,6 +892,76 @@ impl ScriptTask {
         true
     }
 
+    fn categorize_msg(&self, msg: &MixedMessage) -> ScriptTaskEventCategory {
+        match *msg {
+            MixedMessage::FromConstellation(ref inner_msg) => {
+                match *inner_msg {
+                    ConstellationControlMsg::SendEvent(_, _) =>
+                        ScriptTaskEventCategory::DomEvent,
+                    _ => ScriptTaskEventCategory::ConstellationMsg
+                }
+            },
+            MixedMessage::FromDevtools(_) => ScriptTaskEventCategory::DevtoolsMsg,
+            MixedMessage::FromImageCache(_) => ScriptTaskEventCategory::ImageCacheMsg,
+            MixedMessage::FromScript(ref inner_msg) => {
+                match *inner_msg {
+                    MainThreadScriptMsg::Common(CommonScriptMsg::RunnableMsg(ref category, _)) =>
+                        *category,
+                    _ => ScriptTaskEventCategory::ScriptEvent
+                }
+            }
+        }
+    }
+
+    fn profile_event<F, R>(&self, category: ScriptTaskEventCategory, f: F) -> R
+        where F: FnOnce() -> R {
+
+        if opts::get().profile_script_events {
+            let start = time::precise_time_ns();
+            let result = f();
+            let end = time::precise_time_ns();
+
+            let duration = end - start;
+
+            let aggregate = {
+                let zero = 0;
+                let perf_profiler_times = self.perf_profiler_times.borrow();
+                let so_far = perf_profiler_times.get(&category).unwrap_or(&zero);
+
+                so_far + duration
+            };
+
+            self.perf_profiler_times.borrow_mut().insert(category, aggregate);
+
+            const NANO: u64 = 1000 * 1000 * 1000;
+            const REPORT_INTERVAL: u64 = 10 * NANO;
+
+            match self.perf_profiler_next_report.get() {
+                None => self.perf_profiler_next_report.set(Some(start + REPORT_INTERVAL)),
+                Some(time) if time <= end => {
+                    self.perf_profiler_next_report.set(Some(end + REPORT_INTERVAL));
+
+                    let stdout = stdout();
+                    let mut stdout = stdout.lock();
+                    writeln!(&mut stdout, "Script task time distribution:").unwrap();
+                    for (c, t) in self.perf_profiler_times.borrow().deref() {
+                        let secs = t / NANO;
+                        let nanos = t % NANO;
+                        writeln!(&mut stdout, "  {:?}: {}.{}s", c, secs, nanos).unwrap();
+                    }
+                    stdout.flush().unwrap();
+
+                    self.perf_profiler_times.borrow_mut().clear();
+                },
+                Some(_) => {}
+            }
+
+            result
+        } else {
+            f()
+        }
+    }
+
     fn handle_msg_from_constellation(&self, msg: ConstellationControlMsg) {
         match msg {
             ConstellationControlMsg::AttachLayout(_) =>
@@ -914,7 +1029,9 @@ impl ScriptTask {
             MainThreadScriptMsg::Common(
                 CommonScriptMsg::FireTimer(TimerSource::FromWorker, _)) =>
                 panic!("Worker timeouts must not be sent to script task"),
-            MainThreadScriptMsg::Common(CommonScriptMsg::RunnableMsg(runnable)) =>
+            MainThreadScriptMsg::Common(CommonScriptMsg::RunnableMsg(_, runnable)) =>
+                // The category of the runnable is ignored by the pattern, however
+                // it is still respected by profiling (see categorize_msg).
                 runnable.handler(),
             MainThreadScriptMsg::Common(CommonScriptMsg::RefcountCleanup(addr)) =>
                 LiveDOMReferences::cleanup(addr),
@@ -1128,7 +1245,7 @@ impl ScriptTask {
         // https://html.spec.whatwg.org/multipage/#the-end step 7
         let addr: Trusted<Document> = Trusted::new(self.get_cx(), doc, self.chan.clone());
         let handler = box DocumentProgressHandler::new(addr.clone(), DocumentProgressTask::Load);
-        self.chan.send(CommonScriptMsg::RunnableMsg(handler)).unwrap();
+        self.chan.send(CommonScriptMsg::RunnableMsg(ScriptTaskEventCategory::DocumentEvent, handler)).unwrap();
 
         let ConstellationChan(ref chan) = self.constellation_chan;
         chan.send(ConstellationMsg::LoadComplete(pipeline)).unwrap();
@@ -1881,7 +1998,7 @@ impl ScriptTask {
         // https://html.spec.whatwg.org/multipage/#the-end step 4
         let addr: Trusted<Document> = Trusted::new(self.get_cx(), document.r(), self.chan.clone());
         let handler = box DocumentProgressHandler::new(addr, DocumentProgressTask::DOMContentLoaded);
-        self.chan.send(CommonScriptMsg::RunnableMsg(handler)).unwrap();
+        self.chan.send(CommonScriptMsg::RunnableMsg(ScriptTaskEventCategory::DocumentEvent, handler)).unwrap();
 
         window.r().set_fragment_name(final_url.fragment.clone());
 

components/util/opts.rs

@@ -123,6 +123,9 @@ pub struct Opts {
     /// profile viewer.
     pub profile_tasks: bool,
 
+    /// Periodically print out on which events script tasks spend their processing time.
+    pub profile_script_events: bool,
+
     /// `None` to disable devtools or `Some` with a port number to start a server to listen to
     /// remote Firefox devtools connections.
     pub devtools_port: Option<u16>,
@@ -213,6 +216,9 @@ pub struct DebugOptions {
     /// Instrument each task, writing the output to a file.
     pub profile_tasks: bool,
 
+    /// Profile which events script tasks spend their time on.
+    pub profile_script_events: bool,
+
     /// Paint borders along layer and tile boundaries.
     pub show_compositor_borders: bool,
 
@@ -265,6 +271,7 @@ impl DebugOptions {
                 "dump-display-list-optimized" => debug_options.dump_display_list_optimized = true,
                 "relayout-event" => debug_options.relayout_event = true,
                 "profile-tasks" => debug_options.profile_tasks = true,
+                "profile-script-events" => debug_options.profile_script_events = true,
                 "show-compositor-borders" => debug_options.show_compositor_borders = true,
                 "show-fragment-borders" => debug_options.show_fragment_borders = true,
                 "show-parallel-paint" => debug_options.show_parallel_paint = true,
@@ -409,6 +416,7 @@ pub fn default_opts() -> Opts {
         relayout_event: false,
         validate_display_list_geometry: false,
         profile_tasks: false,
+        profile_script_events: false,
         resources_path: None,
         sniff_mime_types: false,
         disable_share_style_cache: false,
@@ -594,6 +602,7 @@ pub fn from_cmdline_args(args: &[String]) {
         hard_fail: opt_match.opt_present("f"),
         bubble_inline_sizes_separately: bubble_inline_sizes_separately,
         profile_tasks: debug_options.profile_tasks,
+        profile_script_events: debug_options.profile_script_events,
         trace_layout: debug_options.trace_layout,
         devtools_port: devtools_port,
         webdriver_port: webdriver_port,