fix(FEC-10662): source removed before destroy process finish (#503)

Issue: source has been removed from video tag before destroy has been finished.
Solution: wait for mediaSource destroy before removing the src from video tag.

src/engines/html5/html5.js

@@ -50,7 +50,7 @@ export default class Html5 extends FakeEventTarget implements IEngine {
    */
   _canLoadMediaSourceAdapterPromise: Promise<*>;
   _droppedFramesWatcher: ?DroppedFramesWatcher;
-
+  _reset: boolean = false;
   /**
    * The html5 class logger.
    * @type {any}
@@ -208,19 +208,26 @@ export default class Html5 extends FakeEventTarget implements IEngine {
    * @returns {void}
    */
   reset(): void {
+    if (this._reset) return;
+    this._reset = true;
     this._eventManager.removeAll();
     if (this._droppedFramesWatcher) {
       this._droppedFramesWatcher.destroy();
       this._droppedFramesWatcher = null;
     }
-    if (this._mediaSourceAdapter) {
-      this._canLoadMediaSourceAdapterPromise = this._mediaSourceAdapter.destroy();
-      this._mediaSourceAdapter = null;
-    }
-    if (this._el && this._el.src) {
-      Utils.Dom.setAttribute(this._el, 'src', '');
-      Utils.Dom.removeAttribute(this._el, 'src');
-    }
+    this._canLoadMediaSourceAdapterPromise = new Promise((resolve, reject) => {
+      const mediaSourceAdapterDestroyed = this._mediaSourceAdapter ? this._mediaSourceAdapter.destroy() : Promise.resolve();
+      if (this._el && this._el.src) {
+        mediaSourceAdapterDestroyed.then(() => {
+          Utils.Dom.setAttribute(this._el, 'src', '');
+          Utils.Dom.removeAttribute(this._el, 'src');
+          resolve();
+        }, reject);
+      } else {
+        mediaSourceAdapterDestroyed.then(resolve, reject);
+      }
+    });
+    this._mediaSourceAdapter = null;
   }
 
   /**
@@ -972,6 +979,7 @@ export default class Html5 extends FakeEventTarget implements IEngine {
    */
   _init(source: PKMediaSourceObject, config: Object): void {
     this._config = config;
+    this._reset = false;
     this._loadMediaSourceAdapter(source);
     this.attach();
   }