View source for Browser.warn chromeless window.infobar

==Background==
Web authors who use [http://developer.mozilla.org/en/docs/window.open <code>window.open()</code>] to create new browser windows have the option of specifying [http://developer.mozilla.org/en/docs/window.open#Toolbar_and_chrome_features whether the Location Bar is visible].

Oftentimes this obfuscates the popup’s origin. This preference determined whether to show a <code>browsermessage</code> information bar with the URL of the popup’s opener when the [[:Category:Location Bar|Location Bar]] was hidden. However, the eventual fix for the [https://bugzilla.mozilla.org/show_bug.cgi?id=22183 original bug] used an alternate method to achieve this, and this preference was removed.