Rework “visible” to “throttled” in constellation + script + compositor (#31816)

components/script/dom/document.rs

@@ -1966,7 +1966,7 @@ impl Document {
 
         // If we are running 'fake' animation frames, we unconditionally
         // set up a one-shot timer for script to execute the rAF callbacks.
-        if self.is_faking_animation_frames() && self.window().visible() {
+        if self.is_faking_animation_frames() && !self.window().throttled() {
             warn!("Scheduling fake animation frame. Animation frames tick too fast.");
             let callback = FakeRequestAnimationFrameCallback {
                 document: Trusted::new(self),

components/script/dom/htmliframeelement.rs

@@ -87,7 +87,7 @@ pub struct HTMLIFrameElement {
     sandbox: MutNullableDom<DOMTokenList>,
     sandbox_allowance: Cell<Option<SandboxAllowance>>,
     load_blocker: DomRefCell<Option<LoadBlocker>>,
-    visibility: Cell<bool>,
+    throttled: Cell<bool>,
 }
 
 impl HTMLIFrameElement {
@@ -438,7 +438,7 @@ impl HTMLIFrameElement {
             sandbox: Default::default(),
             sandbox_allowance: Cell::new(None),
             load_blocker: DomRefCell::new(None),
-            visibility: Cell::new(true),
+            throttled: Cell::new(false),
         }
     }
 
@@ -473,9 +473,9 @@ impl HTMLIFrameElement {
         self.top_level_browsing_context_id.get()
     }
 
-    pub fn change_visibility_status(&self, visibility: bool) {
-        if self.visibility.get() != visibility {
-            self.visibility.set(visibility);
+    pub fn set_throttled(&self, throttled: bool) {
+        if self.throttled.get() != throttled {
+            self.throttled.set(throttled);
         }
     }
 

components/script/dom/window.rs

@@ -349,7 +349,7 @@ pub struct Window {
     #[no_trace]
     player_context: WindowGLContext,
 
-    visible: Cell<bool>,
+    throttled: Cell<bool>,
 
     /// A shared marker for the validity of any cached layout values. A value of true
     /// indicates that any such values remain valid; any new layout that invalidates
@@ -2454,18 +2454,18 @@ impl Window {
         self.Document().react_to_environment_changes();
     }
 
-    /// Slow down/speed up timers based on visibility.
-    pub fn alter_resource_utilization(&self, visible: bool) {
-        self.visible.set(visible);
-        if visible {
-            self.upcast::<GlobalScope>().speed_up_timers();
-        } else {
+    /// Set whether to use less resources by running timers at a heavily limited rate.
+    pub fn set_throttled(&self, throttled: bool) {
+        self.throttled.set(throttled);
+        if throttled {
             self.upcast::<GlobalScope>().slow_down_timers();
+        } else {
+            self.upcast::<GlobalScope>().speed_up_timers();
         }
     }
 
-    pub fn visible(&self) -> bool {
-        self.visible.get()
+    pub fn throttled(&self) -> bool {
+        self.throttled.get()
     }
 
     pub fn unminified_js_dir(&self) -> Option<String> {
@@ -2621,7 +2621,7 @@ impl Window {
             userscripts_path,
             replace_surrogates,
             player_context,
-            visible: Cell::new(true),
+            throttled: Cell::new(false),
             layout_marker: DomRefCell::new(Rc::new(Cell::new(true))),
             current_event: DomRefCell::new(None),
         });