If the mathml.disabled preference is true, treat <math> and other MathML
elements as generic XML elements.
This patch disables the rendering code of MathML however preserves the
namespace so to reduce the breakage.
Original patch by: Kathy Brade <brade@pearlcrescent.com>
MozReview-Commit-ID: A2f2Q2b4eqR
--HG--
extra : rebase_source : 3c8530816727c01b68a831d560bfe16e7b02bd9d
Jonathan Kingston
Andrew McCreight
Kyle Huey