chore: Update AbortSignal polyfill for new compiler (shaka-project#7176)

This upgrades the compiler and reworks the AbortSignal polyfill to match
the new compiler externs for that class. This is important to make Shaka
Player compatible with the latest compilers in use inside Google.

Note that the Closure compiler is deprecated, so this should be our
final upgrade. We will some day move to TypeScript.

This does _not_ update the Closure library, because the latest version
causes failures we don't understand in the loading mechanism in
test/test/boot.js.

Author: joeyparrish

lib/polyfill/abort_controller.js

@@ -58,14 +58,11 @@ shaka.polyfill.AbortController = class {
 
 /**
  * @summary A polyfill for AbortSignal, part of the AbortController API.
- * @implements {AbortSignal}
+ * @extends AbortSignal
  */
-shaka.polyfill.AbortController.AbortSignal =
-class extends shaka.util.FakeEventTarget {
+shaka.polyfill.AbortController.AbortSignal = class {
   /** */
   constructor() {
-    super();
-
     /** @private {boolean} */
     this.aborted_ = false;
 
@@ -74,19 +71,37 @@ class extends shaka.util.FakeEventTarget {
 
     /** @type {?function(!Event)} */
     this.onabort = null;
+
+    /** @private {!shaka.util.FakeEventTarget} */
+    this.eventTarget_ = new shaka.util.FakeEventTarget();
+  }
+
+  /** @override */
+  addEventListener(type, listener, options) {
+    return this.eventTarget_.addEventListener(type, listener, options);
+  }
+
+  /** @override */
+  removeEventListener(type, listener, options) {
+    return this.eventTarget_.removeEventListener(type, listener, options);
+  }
+
+  /** @override */
+  dispatchEvent(event) {
+    return this.eventTarget_.dispatchEvent(event);
   }
 
   /** @override */
   get aborted() {
     return this.aborted_;
   }
 
-  /** @return {*} */
+  /** @override */
   get reason() {
     return this.reason_;
   }
 
-  /** @return {void} */
+  /** @override */
   throwIfAborted() {
     if (this.aborted_) {
       throw this.reason_;
@@ -119,21 +134,14 @@ class extends shaka.util.FakeEventTarget {
     this.dispatchEvent(event);
   }
 
-
-  /**
-   * @param {*=} reason
-   * @return {!AbortSignal}
-   */
+  /** @override */
   static abort(reason) {
     const signal = new shaka.polyfill.AbortController.AbortSignal();
     signal.doAbort_(reason);
     return signal;
   }
 
-  /**
-   * @param {number} timeMs
-   * @return {!AbortSignal}
-   */
+  /** @override */
   static timeout(timeMs) {
     const signal = new shaka.polyfill.AbortController.AbortSignal();
 

package-lock.json

@@ -31,8 +31,8 @@
     "eslint-plugin-shaka-rules": "file:./build/eslint-plugin-shaka-rules",
     "esprima": "^4.0.1",
     "fontfaceonload": "^1.0.2",
-    "google-closure-compiler-java": "^20221102.0.0",
-    "google-closure-deps": "^20221102.0.0",
+    "google-closure-compiler-java": "^20240317.0.0",
+    "google-closure-deps": "^20230802.0.0",
     "google-closure-library": "^20221102.0.0",
     "htmlhint": "^1.1.3",
     "jasmine-ajax": "^4.0.0",