Reftest for video poster frame

components/script/dom/htmlmediaelement.rs

@@ -57,6 +57,7 @@ use net_traits::request::{CredentialsMode, Destination, RequestInit};
 use net_traits::{CoreResourceMsg, FetchChannels, FetchMetadata, FetchResponseListener, Metadata};
 use net_traits::{NetworkError, ResourceFetchTiming, ResourceTimingType};
 use script_layout_interface::HTMLMediaData;
+use servo_config::prefs::PREFS;
 use servo_media::player::frame::{Frame, FrameRenderer};
 use servo_media::player::{PlaybackState, Player, PlayerError, PlayerEvent, StreamType};
 use servo_media::ServoMedia;
@@ -1098,6 +1099,14 @@ impl HTMLMediaElement {
                 .unwrap()
                 .render_poster_frame(image);
             self.upcast::<Node>().dirty(NodeDamage::OtherNodeDamage);
+            if let Some(testing_on) = PREFS.get("media.testing.enabled").as_boolean() {
+                if !testing_on {
+                    return;
+                }
+                let window = window_from_node(self);
+                let task_source = window.task_manager().media_element_task_source();
+                task_source.queue_simple_event(self.upcast(), atom!("postershown"), &window);
+            }
         }
     }
 

components/script/dom/htmlvideoelement.rs

@@ -6,6 +6,7 @@ use crate::dom::attr::Attr;
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::HTMLVideoElementBinding;
 use crate::dom::bindings::codegen::Bindings::HTMLVideoElementBinding::HTMLVideoElementMethods;
+use crate::dom::bindings::codegen::Bindings::WindowBinding::WindowBinding::WindowMethods;
 use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::refcounted::Trusted;
 use crate::dom::bindings::reflector::DomObject;
@@ -113,6 +114,11 @@ impl HTMLVideoElement {
         // Step 3.
         let poster_url = match ServoUrl::parse(poster_url) {
             Ok(url) => url,
+            Err(url::ParseError::RelativeUrlWithoutBase) => {
+                let window = window_from_node(self);
+                let url = window.Location().get_url();
+                url.join(&poster_url).unwrap()
+            },
             Err(_) => return,
         };
 
@@ -219,6 +225,10 @@ impl HTMLVideoElementMethods for HTMLVideoElement {
 
     // https://html.spec.whatwg.org/multipage/#dom-video-poster
     make_setter!(SetPoster, "poster");
+
+    // For testing purposes only. This is not an event from
+    // https://html.spec.whatwg.org/multipage/#dom-video-poster
+    event_handler!(postershown, GetOnpostershown, SetOnpostershown);
 }
 
 impl VirtualMethods for HTMLVideoElement {

components/script/dom/location.rs

@@ -37,7 +37,7 @@ impl Location {
         )
     }
 
-    fn get_url(&self) -> ServoUrl {
+    pub fn get_url(&self) -> ServoUrl {
         self.window.get_url()
     }
 

components/script/dom/webidls/HTMLVideoElement.webidl

@@ -13,3 +13,8 @@ interface HTMLVideoElement : HTMLMediaElement {
   readonly attribute unsigned long videoHeight;
   [CEReactions] attribute DOMString poster;
 };
+
+partial interface HTMLVideoElement {
+  [Pref="media.testing.enabled"]
+  attribute EventHandler onpostershown;
+};