[MD History] Hide empty synced device cards.

chrome/browser/resources/md_history/lazy_load.crisper.js

 Polymer({
   is: 'iron-collapse',
   behaviors: [ Polymer.IronResizableBehavior ],
   properties: {
     horizontal: {
       type: Boolean,
       value: false,
       observer: '_horizontalChanged'
     },
     opened: {
@@ skipping 2196 matching lines @@
     if (guestSession) return true;
     return signInState && syncedDevicesLength == 0;
   },
   showSignInGuide: function(signInState, guestSession) {
     var show = !signInState && !guestSession;
     if (show) {
       md_history.BrowserService.getInstance().recordAction('Signin_Impression_FromRecentTabs');
     }
     return show;
   },
-  noSyncedTabsMessage: function(fetchingSyncedTabs) {
-    return loadTimeData.getString(fetchingSyncedTabs ? 'loading' : 'noSyncedResults');
+  noSyncedTabsMessage: function() {
+    var stringName = this.fetchingSyncedTabs_ ? 'loading' : 'noSyncedResults';
+    if (this.searchTerm !== '') stringName = 'noSearchResults';
+    return loadTimeData.getString(stringName);
   },
   updateSyncedDevices: function(sessionList) {
     this.fetchingSyncedTabs_ = false;
     if (!sessionList) return;
     if (sessionList.length > 0 && !this.hasSeenForeignData_) {
       this.hasSeenForeignData_ = true;
       md_history.BrowserService.getInstance().recordHistogram(SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.HAS_FOREIGN_DATA, SyncedTabsHistogram.LIMIT);
     }
     var updateCount = Math.min(sessionList.length, this.syncedDevices_.length);
     for (var i = 0; i < updateCount; i++) {
       var oldDevice = this.syncedDevices_[i];
       if (oldDevice.tag != sessionList[i].tag || oldDevice.timestamp != sessionList[i].timestamp) {
-        this.splice('syncedDevices_', i, 1, this.createInternalDevice_(sessionList[i]));
+        var device = this.createInternalDevice_(sessionList[i]);
+        if (device.tabs.length != 0) this.splice('syncedDevices_', i, 1, device);
       }
     }
     if (sessionList.length >= this.syncedDevices_.length) {
       for (var i = updateCount; i < sessionList.length; i++) {
-        this.push('syncedDevices_', this.createInternalDevice_(sessionList[i]));
+        var device = this.createInternalDevice_(sessionList[i]);
+        if (device.tabs.length != 0) this.push('syncedDevices_', device);
       }
     } else {
       this.splice('syncedDevices_', updateCount, this.syncedDevices_.length - updateCount);
     }
   },
   tabSyncDisabled: function() {
     this.fetchingSyncedTabs_ = false;
     this.clearDisplayedSyncedDevices_();
   },
   signInStateChanged_: function() {
@@ skipping 1035 matching lines @@
     var cl = this.$.selectionBar.classList;
     if (cl.contains('expand')) {
       cl.remove('expand');
       cl.add('contract');
       this._positionBar(this._pos.width, this._pos.left);
     } else if (cl.contains('contract')) {
       cl.remove('contract');
     }
   }
 });