Instead of `<xul:hbox class="textbox-input-box">`, consumers now should use
`<xul:moz-input-box />`. This covers the normal case and also handles
[spellcheck=true] while sharing much of the code within one class.
MozReview-Commit-ID: DjvT8sFq3SQ
--HG--
rename : toolkit/content/widgets/textbox.xml => toolkit/content/widgets/textbox.js
Test changes for removal of PopupBoxObject and popup.xml methods, some reflow tests now have different stacks now that they are not going through popup.xml binding methods, test_popupanchor.xul changes due to need to wait for popuppositioned event after resizing. The old code would just adjust the arrow directly when sizeTo was called, but the new code does this through an asynchronous popuppositioned event. Changes to some places that check for XULElement class.
--HG--
rename : dom/webidl/PopupBoxObject.webidl => dom/webidl/XULPopupElement.webidl
rename : layout/xul/PopupBoxObject.cpp => dom/xul/XULPopupElement.cpp
rename : layout/xul/PopupBoxObject.h => dom/xul/XULPopupElement.h
