Add restart on Backbone route change

pace.coffee

@@ -27,6 +27,10 @@ defaultOptions =
   # means ajax navigation has occured)
   restartOnPushState: true
 
+  # Should pace automatically restart when a Backbone route change occurs?  Can also be an
+  # array of route names.  Ignored if Backbone.js is not included on the page.
+  restartOnBackboneRoute: true
+
   elements:
     # How frequently in ms should we check for the elements being tested for
     # using the element monitor?
@@ -411,6 +415,24 @@ if window.history.replaceState?
 
     _replaceState.apply window.history, arguments
 
+if options.restartOnBackboneRoute
+  # Bind in a timeout, as it's possible Backbone hasen't been
+  # included yet
+  setTimeout ->
+    return unless window.Backbone?
+
+    Backbone.History.on 'route', (router, name) ->
+      return unless rule = options.restartOnBackboneRoute
+
+      if typeof rule is 'object'
+        # It's an array of route names
+        for routeName in rule when routeName is name
+          Pace.restart()
+          break
+      else
+        Pace.restart()
+  , 0
+
 SOURCE_KEYS =
   ajax: AjaxMonitor
   elements: ElementMonitor