Fix HEAD.

The typescript compiler became more strict.

Additionally, there was a race-condition between moving to
material-icons and Change 340971 and Change 341047

Release-Notes: skip
Change-Id: I2572b726109a62853eb84da4defbc2ce199faf33
diff --git a/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.ts b/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.ts
index c8a737f..6da1c2c 100644
--- a/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header_test.ts
@@ -65,13 +65,14 @@
           </gr-endpoint-decorator>
         </div>
         <div class="accountContainer" id="accountContainer">
-          <iron-icon
+          <span
             aria-label="Hide Searchbar"
-            icon="gr-icons:search"
+            class="material-icon"
             id="mobileSearch"
             role="button"
           >
-          </iron-icon>
+            search
+          </span>
           <a class="loginButton" href="/login"> Sign in </a>
           <a
             aria-label="Settings"
diff --git a/polygerrit-ui/app/utils/async-util.ts b/polygerrit-ui/app/utils/async-util.ts
index 71e0a9c..4281f43 100644
--- a/polygerrit-ui/app/utils/async-util.ts
+++ b/polygerrit-ui/app/utils/async-util.ts
@@ -106,10 +106,10 @@
 export const DELAYED_CANCELLATION = Symbol('Delayed Cancellation');
 
 export class DelayedPromise<T> extends Promise<T> {
-  private readonly resolve: (value: PromiseLike<T> | T) => void;
+  private resolve: (value: PromiseLike<T> | T) => void;
 
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  private readonly reject: (reason?: any) => void;
+  private reject: (reason?: any) => void;
 
   private timer: number | undefined;
 
@@ -167,11 +167,11 @@
   //    that default behaviour by redefining its @@species property.
   // NOTE: This is required otherwise .then and .catch on a DelayedPromise
   // will try to instantiate a DelayedPromise with 'resolve, reject' arguments.
-  static get [Symbol.species]() {
+  static override get [Symbol.species]() {
     return Promise;
   }
 
-  get [Symbol.toStringTag]() {
+  override get [Symbol.toStringTag]() {
     return 'DelayedPromise';
   }
 }