Revert "Bug 505988 - [Project Explorer] Navigation buttons disappear after working set switch"

This reverts commit fabbb8db7d601c90cfceb3a7618111061f79ec4a.
diff --git a/bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/CommonNavigatorActionGroup.java b/bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/CommonNavigatorActionGroup.java
index b6b1cbe..a050a40 100644
--- a/bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/CommonNavigatorActionGroup.java
+++ b/bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/CommonNavigatorActionGroup.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2003, 2018 IBM Corporation and others.
+ * Copyright (c) 2003, 2015 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -115,7 +115,6 @@
 				commonNavigator.updateTitle();
 				IActionBars actionBars= commonNavigator.getViewSite().getActionBars();
 				updateToolBar(actionBars.getToolBarManager());
-				actionBars.updateActionBars();
 			}
 		});
 
diff --git a/bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/framelist/TreeViewerFrameSource.java b/bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/framelist/TreeViewerFrameSource.java
index b0426a6..9c40b72 100755
--- a/bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/framelist/TreeViewerFrameSource.java
+++ b/bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/framelist/TreeViewerFrameSource.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2018 IBM Corporation and others.
+ * Copyright (c) 2000, 2015 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -161,7 +161,7 @@
      * Calls <code>frameChanged</code> when the current frame changes.
      */
     protected void handlePropertyChange(PropertyChangeEvent event) {
-        if (FrameList.P_CURRENT_FRAME.equals(event.getProperty()) || FrameList.P_RESET.equals(event.getProperty())) {
+        if (FrameList.P_CURRENT_FRAME.equals(event.getProperty())) {
             frameChanged((TreeFrame) event.getNewValue());
         }
     }