Bug 1089815 - View source print preview browser does not have a message manager. r=Mossop.

<xul:browser>'s do not get messageManager's constructed for them unless they
have their type attribute set to "content", "content-targetable", or
"content-primary". This patch updates the view source print preview browser
with that type attribute, and also updates the PrintUtils documentation to
mention this requirement.

--HG--
extra : amend_source : 12638e8fd0c0da9b3036d7892d02a360b7513ec5