Add super.wasShown() method to WebAudioView.wasShown()

Currently when user switches back to the WebAudio panel from the other
panels, it does not update the realtime data anymore. This CL fixes
it by calling super.wasShown() in the view's wasShown() method,
starting the update loop again.

Bug: 971806
Change-Id: Ie15a07a2c8ec73425216bba12f86450b6650675b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1648702
Commit-Queue: Hongchan Choi <[email protected]>
Reviewed-by: Erik Luo <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#666890}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: ad51088fd25c8538bd730a326e10986862875f8a
diff --git a/front_end/web_audio/WebAudioView.js b/front_end/web_audio/WebAudioView.js
index 2fa72c9..9944ea7 100644
--- a/front_end/web_audio/WebAudioView.js
+++ b/front_end/web_audio/WebAudioView.js
@@ -50,6 +50,7 @@
    * @override
    */
   wasShown() {
+    super.wasShown();
     for (const model of SDK.targetManager.models(WebAudio.WebAudioModel))
       this._addEventListeners(model);
   }