Chromium team has added ‘Open Link as user’ context menu entry. You’ll notice this in Chrome Canary build when more than one user uses the browser. Expect this feature to available in future release versions of Chrome.
If you use multiple Profiles in Chrome browser, soon one user’ll be able to open a link from within his browser window on other’s, he just needs to right click on the link and select ‘open link as username’ (check the screenshot below) for that. Selecting the menu entry automatically opens a new window, even if another user’s browser window is not open or running at the time of opening the link.