metrics: Simplify ProgressiveWebMetrics (#35985)

Simply how `ProgressiveWebMetrics` works:

1. Keep only a single struct instead of one in layout and one script
   that both implement the `ProgressiveWebMetrics` trait. Since layout
   and script are the same thread these can now just be a single
   `ProgressiveWebMetrics` struct stored in script.
2. Have the compositor be responsible for informing the Constellation
   (which informs the ScripThread) about paint metrics. This makes
   communication flow one way and removes one dependency between the
   compositor and script (of two).
3. All units tests are moved into the `metrics` crate itself since there
   is only one struct there now.

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

components/script/dom/document.rs

@@ -36,10 +36,7 @@ use hyper_serde::Serde;
 use ipc_channel::ipc;
 use js::rust::{HandleObject, HandleValue};
 use keyboard_types::{Code, Key, KeyState};
-use metrics::{
-    InteractiveFlag, InteractiveMetrics, InteractiveWindow, ProfilerMetadataFactory,
-    ProgressiveWebMetric,
-};
+use metrics::{InteractiveFlag, InteractiveWindow, ProgressiveWebMetrics};
 use mime::{self, Mime};
 use net_traits::CookieSource::NonHTTP;
 use net_traits::CoreResourceMsg::{GetCookiesForUrl, SetCookiesForUrl};
@@ -51,10 +48,11 @@ use net_traits::{FetchResponseListener, IpcSend, ReferrerPolicy};
 use num_traits::ToPrimitive;
 use percent_encoding::percent_decode;
 use profile_traits::ipc as profile_ipc;
-use profile_traits::time::{TimerMetadata, TimerMetadataFrameType, TimerMetadataReflowType};
+use profile_traits::time::TimerMetadataFrameType;
 use script_layout_interface::{PendingRestyle, TrustedNodeAddress};
 use script_traits::{
-    AnimationState, AnimationTickType, ConstellationInputEvent, DocumentActivity, ScriptMsg,
+    AnimationState, AnimationTickType, ConstellationInputEvent, DocumentActivity,
+    ProgressiveWebMetricType, ScriptMsg,
 };
 use servo_arc::Arc;
 use servo_config::pref;
@@ -78,6 +76,7 @@ use webrender_traits::CompositorHitTestResult;
 
 use super::bindings::codegen::Bindings::XPathEvaluatorBinding::XPathEvaluatorMethods;
 use super::clipboardevent::ClipboardEventType;
+use super::performancepainttiming::PerformancePaintTiming;
 use crate::DomTypes;
 use crate::animation_timeline::AnimationTimeline;
 use crate::animations::Animations;
@@ -432,7 +431,7 @@ pub(crate) struct Document {
     /// See <https://html.spec.whatwg.org/multipage/#form-owner>
     form_id_listener_map: DomRefCell<HashMapTracedValues<Atom, HashSet<Dom<Element>>>>,
     #[no_trace]
-    interactive_time: DomRefCell<InteractiveMetrics>,
+    interactive_time: DomRefCell<ProgressiveWebMetrics>,
     #[no_trace]
     tti_window: DomRefCell<InteractiveWindow>,
     /// RAII canceller for Fetch
@@ -3010,7 +3009,7 @@ impl Document {
         // html parsing has finished - set dom content loaded
         self.interactive_time
             .borrow()
-            .maybe_set_tti(self, InteractiveFlag::DOMContentLoaded);
+            .maybe_set_tti(InteractiveFlag::DOMContentLoaded);
 
         // Step 4.2.
         // TODO: client message queue.
@@ -3095,7 +3094,7 @@ impl Document {
             .set_navigation_start(navigation_start);
     }
 
-    pub(crate) fn get_interactive_metrics(&self) -> Ref<InteractiveMetrics> {
+    pub(crate) fn get_interactive_metrics(&self) -> Ref<ProgressiveWebMetrics> {
         self.interactive_time.borrow()
     }
 
@@ -3149,10 +3148,10 @@ impl Document {
             return;
         }
         if self.tti_window.borrow().needs_check() {
-            self.get_interactive_metrics().maybe_set_tti(
-                self,
-                InteractiveFlag::TimeToInteractive(self.tti_window.borrow().get_start()),
-            );
+            self.get_interactive_metrics()
+                .maybe_set_tti(InteractiveFlag::TimeToInteractive(
+                    self.tti_window.borrow().get_start(),
+                ));
         }
     }
 
@@ -3532,6 +3531,37 @@ impl Document {
                 document.root().notify_intersection_observers(CanGc::note());
             }));
     }
+
+    pub(crate) fn handle_paint_metric(
+        &self,
+        metric_type: ProgressiveWebMetricType,
+        metric_value: CrossProcessInstant,
+        first_reflow: bool,
+        can_gc: CanGc,
+    ) {
+        let metrics = self.interactive_time.borrow();
+        match metric_type {
+            ProgressiveWebMetricType::FirstPaint => {
+                metrics.set_first_paint(metric_value, first_reflow)
+            },
+            ProgressiveWebMetricType::FirstContentfulPaint => {
+                metrics.set_first_contentful_paint(metric_value, first_reflow)
+            },
+            ProgressiveWebMetricType::TimeToInteractive => {
+                unreachable!("Unexpected non-paint metric.")
+            },
+        }
+
+        let entry = PerformancePaintTiming::new(
+            self.window.as_global_scope(),
+            metric_type,
+            metric_value,
+            can_gc,
+        );
+        self.window
+            .Performance()
+            .queue_entry(entry.upcast::<PerformanceEntry>(), can_gc);
+    }
 }
 
 fn is_character_value_key(key: &Key) -> bool {
@@ -3688,8 +3718,15 @@ impl Document {
             (DocumentReadyState::Complete, true)
         };
 
-        let interactive_time =
-            InteractiveMetrics::new(window.time_profiler_chan().clone(), url.clone());
+        let frame_type = match window.is_top_level() {
+            true => TimerMetadataFrameType::RootWindow,
+            false => TimerMetadataFrameType::IFrame,
+        };
+        let interactive_time = ProgressiveWebMetrics::new(
+            window.time_profiler_chan().clone(),
+            url.clone(),
+            frame_type,
+        );
 
         let content_type = content_type.unwrap_or_else(|| {
             match is_html_document {
@@ -4704,16 +4741,6 @@ impl Document {
     }
 }
 
-impl ProfilerMetadataFactory for Document {
-    fn new_metadata(&self) -> Option<TimerMetadata> {
-        Some(TimerMetadata {
-            url: String::from(self.url().as_str()),
-            iframe: TimerMetadataFrameType::RootWindow,
-            incremental: TimerMetadataReflowType::Incremental,
-        })
-    }
-}
-
 #[allow(non_snake_case)]
 impl DocumentMethods<crate::DomTypeHolder> for Document {
     // https://dom.spec.whatwg.org/#dom-document-document