change Event.srcElement type to EventTarget and expose it to Worker

Author: FrogTheFrog

baselines/dom.generated.d.ts

@@ -4942,7 +4942,7 @@ interface Event {
     readonly isTrusted: boolean;
     returnValue: boolean;
     /** @deprecated */
-    readonly srcElement: Element | null;
+    readonly srcElement: EventTarget | null;
     /**
      * Returns the object to which event is dispatched (its target).
      */

baselines/webworker.generated.d.ts

@@ -1020,6 +1020,8 @@ interface Event {
      */
     readonly isTrusted: boolean;
     returnValue: boolean;
+    /** @deprecated */
+    readonly srcElement: EventTarget | null;
     /**
      * Returns the object to which event is dispatched (its target).
      */

inputfiles/overridingTypes.json

@@ -2227,8 +2227,7 @@
                 "properties": {
                     "property": {
                         "srcElement": {
-                            "exposed": "Window",
-                            "type": "Element",
+                            "exposed": "Window Worker",
                             "nullable": 1,
                             "deprecated": 1
                         }