Sorry for my bad english, but i found a bug in the page http://www.polymer-project.org/docs/elements/material.html
When i opened the page the browser was not maximized, and the page was in the responsive mode. I clicked to open the left menu, and the right scroll desappeared (a feature to economize space), but in this time i maximized the browser, so the site enter in the desktop mode, but the right scroll continued desappeared.
Sorry for my bad english, but i found a bug in the page http://www.polymer-project.org/docs/elements/material.html
When i opened the page the browser was not maximized, and the page was in the responsive mode. I clicked to open the left menu, and the right scroll desappeared (a feature to economize space), but in this time i maximized the browser, so the site enter in the desktop mode, but the right scroll continued desappeared.