Remove needless '&mut self' from HTMLStyleElementMethods.
Remove needless '&mut self' from HTMLMapElementMethods.
Remove needless '&mut self' from HTMLMediaElementMethods.
Remove needless '&mut self' from HTMLMetaElementMethods.
Remove needless '&mut self' from HTMLMeterElementMethods.
Remove needless '&mut self' from HTMLModElementMethods.
Remove needless '&mut self' from htmlobjectelement.rs.
Remove needless '&mut self' from HTMLOListElementMethods.
Remove needless '&mut self' from HTMLOptGroupElementMethods.
Remove needless '&mut self' from HTMLOptionElementMethods.
Remove needless '&mut self' from HTMLOutputElementMethods.
Remove needless '&mut self' from HTMLParagraphElementMethods.
Remove needless '&mut self' from HTMLParamElementMethods.
Remove needless '&mut self' from HTMLPreElementMethods.
Remove needless '&mut self' from HTMLProgressElementMethods.
Remove needless '&mut self' from HTMLScriptElementMethods.
Remove needless '&mut self' from HTMLSelectElementMethods.
Remove needless '&mut self' from HTMLSourceElementMethods.
Remove needless '&mut self' from HTMLTableCaptionElementMethods.
Remove needless '&mut self' from HTMLTableColElementMethods.