Remove unused sync code

src/components/apphost.js

@@ -230,10 +230,6 @@ const supportedFeatures = function () {
         features.push('htmlvideoautoplay');
     }
 
-    if (browser.edgeUwp) {
-        features.push('sync');
-    }
-
     if (supportsFullscreen()) {
         features.push('fullscreenchange');
     }

src/components/itemContextMenu.js

@@ -290,14 +290,6 @@ export function getCommands(options) {
         });
     }
 
-    if (options.sync !== false && itemHelper.canSync(user, item)) {
-        commands.push({
-            name: globalize.translate('Sync'),
-            id: 'sync',
-            icon: 'sync'
-        });
-    }
-
     if (options.openAlbum !== false && item.AlbumId && item.MediaType !== 'Photo') {
         commands.push({
             name: globalize.translate('ViewAlbum'),

src/components/itemHelper.js

@@ -154,18 +154,6 @@ export function canEditImages (user, item) {
     return itemType !== 'Timer' && itemType !== 'SeriesTimer' && canEdit(user, item) && !isLocalItem(item);
 }
 
-export function canSync (user, item) {
-    if (user && !user.Policy.EnableContentDownloading) {
-        return false;
-    }
-
-    if (isLocalItem(item)) {
-        return false;
-    }
-
-    return item.SupportsSync;
-}
-
 export function canShare (item, user) {
     if (item.Type === 'Program') {
         return false;
@@ -311,7 +299,6 @@ export default {
     canIdentify: canIdentify,
     canEdit: canEdit,
     canEditImages: canEditImages,
-    canSync: canSync,
     canShare: canShare,
     enableDateAddedDisplay: enableDateAddedDisplay,
     canMarkPlayed: canMarkPlayed,

src/components/metadataEditor/metadataEditor.js

@@ -260,7 +260,6 @@ function showMoreMenu(context, button, user) {
             edit: false,
             editImages: true,
             editSubtitles: true,
-            sync: false,
             share: false,
             play: false,
             queue: false,