Auto merge of #25159 - garasubo:fix-composition-event, r=jdm

implement composition event creation in Document.createEvent

Solved the problem mentioned in https://github.com/servo/servo/issues/24724#issuecomment-562326328

Add logic to create composition event for Document.createEvent. This resolved some WPT test failure, so updated the metadata as well

Ref: https://developer.mozilla.org/en-US/docs/Web/API/Document/createEvent

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components/script/dom/compositionevent.rs

@@ -21,6 +21,21 @@ pub struct CompositionEvent {
 }
 
 impl CompositionEvent {
+    pub fn new_inherited() -> CompositionEvent {
+        CompositionEvent {
+            uievent: UIEvent::new_inherited(),
+            data: DOMString::new(),
+        }
+    }
+
+    pub fn new_uninitialized(window: &Window) -> DomRoot<CompositionEvent> {
+        reflect_dom_object(
+            Box::new(CompositionEvent::new_inherited()),
+            window,
+            CompositionEventBinding::Wrap,
+        )
+    }
+
     pub fn new(
         window: &Window,
         type_: DOMString,

components/script/dom/document.rs

@@ -3811,6 +3811,9 @@ impl DocumentMethods for Document {
             "beforeunloadevent" => Ok(DomRoot::upcast(BeforeUnloadEvent::new_uninitialized(
                 &self.window,
             ))),
+            "compositionevent" | "textevent" => Ok(DomRoot::upcast(
+                CompositionEvent::new_uninitialized(&self.window),
+            )),
             "closeevent" => Ok(DomRoot::upcast(CloseEvent::new_uninitialized(
                 self.window.upcast(),
             ))),