Don't resize the display on window.resize events if we are playing ba…

…ck input events. See #37

js/Sim.js

@@ -475,7 +475,13 @@ define( function( require ) {
       // Fit to the window and render the initial scene
       // Can't synchronously do this in Firefox, see https://github.com/phetsims/vegas/issues/55 and
       // https://bugzilla.mozilla.org/show_bug.cgi?id=840412.
-      $( window ).resize( function() { self.resizePending = true; } );
+      $( window ).resize( function() {
+        // Don't resize on window size changes if we are playing back input events.
+        // See https://github.com/phetsims/joist/issues/37
+        if ( !phet.joist.playbackMode ) {
+          self.resizePending = true;
+        }
+      } );
       this.resizeToWindow();
 
       // Kick off checking for updates, if that is enabled