Behavior broken when transitioning between "device mode" and "normal mode"

[freshp86]

Repro steps:

1. Navigate to the demo page https://elements.polymer-project.org/elements/paper-menu-button?view=demo:demo/index.html&active=paper-menu-button.
2. Turn on "device mode" in Chrome (by clicking on the top right icon shown at the following image),
   
3. Reload the page (to ensure that the page loads while device mode is already on).
4. Turn off device mode (by clicking on the same icon).
5. Click on any paper-menu-button in the demo, no menu comes up.

This is reported at https://bugs.chromium.org/p/chromium/issues/detail?id=611382, since it is affecting Chrome's Polymer-ized pages.

/cc @danbeam.

[freshp86]

Actually this bug is more of an issue on a device that has both touch and mouse interfaces (like the Chromebook Pixel). Updated repro steps below

1. Navigate to the demo page https://elements.polymer-project.org/elements/paper-menu-button?view=demo:demo/index.html&active=paper-menu-button.
2. Click (using the mouse) on any paper-menu-button to open a menu, it opens fine.
3. Click (using the mouse) anywhere outside to close the menu, menu does not close.

Same happens if a screen tap is used to open the menu. Basically no matter how a menu is opened, clicking outside does not close the menu, if the device is also a touch device.