Move ownership of the tool-bar's menu buttons into remoting.Toolbar.

remoting/webapp/menu_button.js

Index: remoting/webapp/menu_button.js
diff --git a/remoting/webapp/menu_button.js b/remoting/webapp/menu_button.js
index 73c7642d1e12995b339dc54294ea9219f16a66a0..b41d69a3680d81f7a0b8e65ace3bc8677d496724 100644
--- a/remoting/webapp/menu_button.js
+++ b/remoting/webapp/menu_button.js
@@ -70,7 +70,7 @@ remoting.MenuButton = function(container, opt_onShow, opt_onHide) {
     if (that.onShow_) {
       that.onShow_();
     }
-    that.button_.classList.add(remoting.MenuButton.BUTTON_ACTIVE_CLASS_);
+    that.button_.classList.toggle(remoting.MenuButton.BUTTON_ACTIVE_CLASS_);
     document.body.addEventListener('click', closeHandler, false);
     event.stopPropagation();
   };