Clean up appHost and shell method checking.

src/scripts/shell.js

@@ -1,29 +1,29 @@
 // TODO: This seems like a good candidate for deprecation
 export default {
     enableFullscreen: function() {
-        if (window.NativeShell && window.NativeShell.enableFullscreen) {
+        if (window.NativeShell?.enableFullscreen) {
             window.NativeShell.enableFullscreen();
         }
     },
     disableFullscreen: function() {
-        if (window.NativeShell && window.NativeShell.disableFullscreen) {
+        if (window.NativeShell?.disableFullscreen) {
             window.NativeShell.disableFullscreen();
         }
     },
     openUrl: function(url, target) {
-        if (window.NativeShell) {
+        if (window.NativeShell?.openUrl) {
             window.NativeShell.openUrl(url, target);
         } else {
             window.open(url, target || '_blank');
         }
     },
     updateMediaSession(mediaInfo) {
-        if (window.NativeShell && window.NativeShell.updateMediaSession) {
+        if (window.NativeShell?.updateMediaSession) {
             window.NativeShell.updateMediaSession(mediaInfo);
         }
     },
     hideMediaSession() {
-        if (window.NativeShell && window.NativeShell.hideMediaSession) {
+        if (window.NativeShell?.hideMediaSession) {
             window.NativeShell.hideMediaSession();
         }
     },
@@ -32,7 +32,7 @@ export default {
      * Useful for e.g. remote playback.
      */
     updateVolumeLevel(volume) {
-        if (window.NativeShell && window.NativeShell.updateVolumeLevel) {
+        if (window.NativeShell?.updateVolumeLevel) {
             window.NativeShell.updateVolumeLevel(volume);
         }
     },
@@ -42,7 +42,7 @@ export default {
      * @returns true on success
      */
     downloadFiles(items) {
-        if (window.NativeShell) {
+        if (window.NativeShell?.downloadFile) {
             items.forEach(item => window.NativeShell.downloadFile(item));
             return true;
         }