Move active media session logic to constellation

components/constellation/constellation.rs

@@ -112,6 +112,7 @@ use compositing::SendableFrameTree;
 use crossbeam_channel::{after, never, unbounded, Receiver, Sender};
 use devtools_traits::{ChromeToDevtoolsControlMsg, DevtoolsControlMsg};
 use embedder_traits::{Cursor, EmbedderMsg, EmbedderProxy, EventLoopWaker};
+use embedder_traits::{MediaSessionEvent, MediaSessionPlaybackState};
 use euclid::{default::Size2D as UntypedSize2D, Size2D};
 use gfx::font_cache_thread::FontCacheThread;
 use gfx_traits::Epoch;
@@ -475,8 +476,8 @@ pub struct Constellation<Message, LTF, STF> {
     /// Mechanism to force the compositor to process events.
     event_loop_waker: Option<Box<dyn EventLoopWaker>>,
     
-    /// Browser ID of the active media session, if any.
+    /// Browing context ID of the active media session.
-    active_media_session: Option<TopLevelBrowsingContextId>,
+    active_media_session: Option<BrowsingContextId>,
 }
 
 /// State needed to construct a constellation.
@@ -1778,6 +1779,30 @@ where
                     new_value,
                 );
             },
+            FromScriptMsg::MediaSessionEvent(browsing_context_id, event) => {
+                // Unlikely at this point, but we may receive events coming from
+                // different media sessions, so we set the active media session based
+                // on Playing events.
+                // The last media session claiming to be in playing state is set to
+                // the active media session.
+                // Events coming from inactive media sessions are discarded.
+                if self.active_media_session.is_some() {
+                    match event {
+                        MediaSessionEvent::PlaybackStateChange(ref state) => {
+                            match state {
+                                MediaSessionPlaybackState::Playing => (),
+                                _ => return,
+                            };
+                        },
+                        _ => (),
+                    };
+                }
+                self.active_media_session = Some(browsing_context_id);
+                self.embedder_proxy.send((
+                    Some(source_top_ctx_id),
+                    EmbedderMsg::MediaSessionEvent(event),
+                ));
+            },
         }
     }
 
@@ -5042,8 +5067,7 @@ where
                 );
             },
         };
-        let msg =
+        let msg = ConstellationControlMsg::MediaSessionAction(browsing_context_id, action);
-            ConstellationControlMsg::MediaSessionAction(top_level_browsing_context_id, action);
         let result = match self.pipelines.get(&pipeline_id) {
             None => {
                 return warn!(

components/script/dom/mediasession.rs

@@ -16,9 +16,10 @@ use crate::dom::mediametadata::MediaMetadata;
 use crate::dom::window::Window;
 use crate::script_thread::ScriptThread;
 use dom_struct::dom_struct;
-use embedder_traits::{EmbedderMsg, MediaSessionEvent};
+use embedder_traits::MediaSessionEvent;
-use msg::constellation_msg::TopLevelBrowsingContextId;
+use msg::constellation_msg::BrowsingContextId;
 use script_traits::MediaSessionActionType;
+use script_traits::ScriptMsg;
 use std::collections::HashMap;
 use std::rc::Rc;
 
@@ -39,7 +40,7 @@ pub struct MediaSession {
 
 impl MediaSession {
     #[allow(unrooted_must_root)]
-    fn new_inherited(browsing_context_id: TopLevelBrowsingContextId) -> MediaSession {
+    fn new_inherited(browsing_context_id: BrowsingContextId) -> MediaSession {
         let media_session = MediaSession {
             reflector_: Reflector::new(),
             metadata: Default::default(),
@@ -52,7 +53,7 @@ impl MediaSession {
     }
 
     pub fn new(window: &Window) -> DomRoot<MediaSession> {
-        let browsing_context_id = window.window_proxy().top_level_browsing_context_id();
+        let browsing_context_id = window.window_proxy().browsing_context_id();
         reflect_dom_object(
             Box::new(MediaSession::new_inherited(browsing_context_id)),
             window,
@@ -74,7 +75,8 @@ impl MediaSession {
     pub fn send_event(&self, event: MediaSessionEvent) {
         let global = self.global();
         let window = global.as_window();
-        window.send_to_embedder(EmbedderMsg::MediaSessionEvent(event));
+        let browsing_context_id = window.window_proxy().browsing_context_id();
+        window.send_to_constellation(ScriptMsg::MediaSessionEvent(browsing_context_id, event));
     }
 }
 
@@ -121,10 +123,7 @@ impl MediaSessionMethods for MediaSession {
 impl Drop for MediaSession {
     fn drop(&mut self) {
         let global = self.global();
-        let browsing_context_id = global
+        let browsing_context_id = global.as_window().window_proxy().browsing_context_id();
-            .as_window()
-            .window_proxy()
-            .top_level_browsing_context_id();
         ScriptThread::remove_media_session(browsing_context_id);
     }
 }

components/script/dom/navigator.rs

@@ -194,7 +194,7 @@ impl NavigatorMethods for Navigator {
     /// https://w3c.github.io/mediasession/#dom-navigator-mediasession
     fn MediaSession(&self) -> DomRoot<MediaSession> {
         self.mediasession.or_init(|| {
-            // There is a single MediaSession instance per top level browsing context
+            // There is a single MediaSession instance per browsing context
             // and only one active MediaSession globally.
             //
             // MediaSession creation can happen in two cases:
@@ -206,7 +206,7 @@ impl NavigatorMethods for Navigator {
             // the script thread.
             let global = self.global();
             let window = global.as_window();
-            let browsing_context_id = window.window_proxy().top_level_browsing_context_id();
+            let browsing_context_id = window.window_proxy().browsing_context_id();
             match ScriptThread::get_media_session(browsing_context_id) {
                 Some(session) => session,
                 None => MediaSession::new(window),

components/script/script_thread.rs

@@ -701,7 +701,7 @@ pub struct ScriptThread {
     /// The MediaSessions known by this thread, if any.
     /// There can only be one active MediaSession.
     /// The constellation has the BrowsingContextId of the active MediaSession, if any.
-    media_sessions: DomRefCell<HashMap<TopLevelBrowsingContextId, Dom<MediaSession>>>,
+    media_sessions: DomRefCell<HashMap<BrowsingContextId, Dom<MediaSession>>>,
 }
 
 /// In the event of thread panic, all data on the stack runs its destructor. However, there
@@ -3938,7 +3938,7 @@ impl ScriptThread {
 
     fn handle_media_session_action(
         &self,
-        browsing_context_id: TopLevelBrowsingContextId,
+        browsing_context_id: BrowsingContextId,
         action: MediaSessionActionType,
     ) {
         match self.media_sessions.borrow().get(&browsing_context_id) {
@@ -3973,7 +3973,7 @@ impl ScriptThread {
 
     pub fn register_media_session(
         media_session: &MediaSession,
-        browsing_context_id: TopLevelBrowsingContextId,
+        browsing_context_id: BrowsingContextId,
     ) {
         SCRIPT_THREAD_ROOT.with(|root| {
             let script_thread = unsafe { &*root.get().unwrap() };
@@ -3984,7 +3984,7 @@ impl ScriptThread {
         })
     }
 
-    pub fn remove_media_session(browsing_context_id: TopLevelBrowsingContextId) {
+    pub fn remove_media_session(browsing_context_id: BrowsingContextId) {
         SCRIPT_THREAD_ROOT.with(|root| {
             let script_thread = unsafe { &*root.get().unwrap() };
             script_thread
@@ -3995,7 +3995,7 @@ impl ScriptThread {
     }
 
     pub fn get_media_session(
-        browsing_context_id: TopLevelBrowsingContextId,
+        browsing_context_id: BrowsingContextId,
     ) -> Option<DomRoot<MediaSession>> {
         SCRIPT_THREAD_ROOT.with(|root| {
             let script_thread = unsafe { &*root.get().unwrap() };

components/script_traits/lib.rs

@@ -389,7 +389,7 @@ pub enum ConstellationControlMsg {
     /// Notifies the script thread about a new recorded paint metric.
     PaintMetric(PipelineId, ProgressiveWebMetricType, u64),
     /// Notifies the media session about a user requested media session action.
-    MediaSessionAction(TopLevelBrowsingContextId, MediaSessionActionType),
+    MediaSessionAction(BrowsingContextId, MediaSessionActionType),
 }
 
 impl fmt::Debug for ConstellationControlMsg {

components/script_traits/script_msg.rs

@@ -17,7 +17,7 @@ use crate::WorkerGlobalScopeInit;
 use crate::WorkerScriptLoadOrigin;
 use canvas_traits::canvas::{CanvasId, CanvasMsg};
 use devtools_traits::{ScriptToDevtoolsControlMsg, WorkerId};
-use embedder_traits::EmbedderMsg;
+use embedder_traits::{EmbedderMsg, MediaSessionEvent};
 use euclid::default::Size2D as UntypedSize2D;
 use euclid::Size2D;
 use gfx_traits::Epoch;
@@ -306,6 +306,7 @@ impl fmt::Debug for ScriptMsg {
             GetClientWindow(..) => "GetClientWindow",
             GetScreenSize(..) => "GetScreenSize",
             GetScreenAvailSize(..) => "GetScreenAvailSize",
+            MediaSessionEvent(..) => "MediaSessionEvent",
         };
         write!(formatter, "ScriptMsg::{}", variant)
     }

components/servo/lib.rs

@@ -83,7 +83,6 @@ use constellation::{Constellation, InitialConstellationState, UnprivilegedPipeli
 use constellation::{FromCompositorLogger, FromScriptLogger};
 use crossbeam_channel::{unbounded, Sender};
 use embedder_traits::{EmbedderMsg, EmbedderProxy, EmbedderReceiver, EventLoopWaker};
-use embedder_traits::{MediaSessionEvent, MediaSessionPlaybackState};
 use env_logger::Builder as EnvLoggerBuilder;
 use euclid::{Scale, Size2D};
 #[cfg(all(
@@ -272,8 +271,6 @@ pub struct Servo<Window: WindowMethods + 'static + ?Sized> {
     embedder_events: Vec<(Option<BrowserId>, EmbedderMsg)>,
     profiler_enabled: bool,
     webgl_thread_data: Option<Rc<WebGLMainThread>>,
-    /// Browser ID of the active media session, if any.
-    active_media_session: Option<BrowserId>,
 }
 
 #[derive(Clone)]
@@ -560,7 +557,6 @@ where
             embedder_events: Vec::new(),
             profiler_enabled: false,
             webgl_thread_data,
-            active_media_session: None,
         }
     }
 
@@ -750,31 +746,6 @@ where
                     self.embedder_events.push(event);
                 },
 
-                (EmbedderMsg::MediaSessionEvent(event), ShutdownState::NotShuttingDown) => {
-                    // Unlikely at this point, but we may receive events coming from
-                    // different media sessions, so we set the active media session based
-                    // on Playing events.
-                    // The last media session claiming to be in playing state is set to
-                    // the active media session.
-                    // Events coming from inactive media sessions are discarded.
-                    if self.active_media_session.is_some() {
-                        match event {
-                            MediaSessionEvent::PlaybackStateChange(ref state) => {
-                                match state {
-                                    MediaSessionPlaybackState::Playing => (),
-                                    _ => return,
-                                };
-                            },
-                            _ => (),
-                        };
-                    }
-                    self.active_media_session = top_level_browsing_context;
-                    self.embedder_events.push((
-                        top_level_browsing_context,
-                        EmbedderMsg::MediaSessionEvent(event),
-                    ));
-                },
-
                 (msg, ShutdownState::NotShuttingDown) => {
                     self.embedder_events.push((top_level_browsing_context, msg));
                 },