--- a/layout/mathml/nsMathMLmactionFrame.cpp
+++ b/layout/mathml/nsMathMLmactionFrame.cpp
@@ -64,17 +64,16 @@
 //
 // <maction> -- bind actions to a subexpression - implementation
 //
 
 #define NS_MATHML_ACTION_TYPE_NONE         0
 #define NS_MATHML_ACTION_TYPE_TOGGLE       1
 #define NS_MATHML_ACTION_TYPE_STATUSLINE   2
 #define NS_MATHML_ACTION_TYPE_TOOLTIP      3 // unsupported
-#define NS_MATHML_ACTION_TYPE_RESTYLE      4
 
 
 nsIFrame*
 NS_NewMathMLmactionFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
   return new (aPresShell) nsMathMLmactionFrame(aContext);
 }
 
@@ -123,47 +122,16 @@ nsMathMLmactionFrame::Init(nsIContent*  
     }
 
     if (NS_MATHML_ACTION_TYPE_NONE == mActionType) {
       // expected statusline prefix (11ch)...
       if (11 < value.Length() && 0 == value.Find("statusline#"))
         mActionType = NS_MATHML_ACTION_TYPE_STATUSLINE;
     }
 
-    if (NS_MATHML_ACTION_TYPE_NONE == mActionType) {
-      // expected restyle prefix (8ch)...
-      if (8 < value.Length() && 0 == value.Find("restyle#")) {
-        mActionType = NS_MATHML_ACTION_TYPE_RESTYLE;
-        mRestyle = value;
-
-        // Here is the situation:
-        // When the attribute [actiontype="restyle#id"] is set, the Style System has
-        // given us the associated style. But we want to start with our default style.
-
-        // So... first, remove the attribute actiontype="restyle#id"
-        // XXXbz this is pretty messed up, since this can change whether we
-        // should have a frame at all.  This really needs a better solution.
-        PRBool notify = PR_FALSE; // don't trigger a reflow yet!
-        aContent->UnsetAttr(kNameSpaceID_None, nsGkAtoms::actiontype_, notify);
-
-        // then, re-resolve our style
-        nsStyleContext* parentStyleContext = GetStyleContext()->GetParent();
-        newStyleContext = PresContext()->StyleSet()->
-          ResolveStyleFor(aContent->AsElement(), parentStyleContext);
-
-        if (!newStyleContext) 
-          mRestyle.Truncate();
-        else {
-          if (newStyleContext != GetStyleContext())
-            SetStyleContextWithoutNotification(newStyleContext);
-          else
-            mRestyle.Truncate();
-        }
-      }
-    }
   }
 
   // Let the base class do the rest
   return nsMathMLContainerFrame::Init(aContent, aParent, aPrevInFlow);
 }
 
 NS_IMETHODIMP
 nsMathMLmactionFrame::TransmitAutomaticData() {
@@ -435,26 +403,9 @@ nsMathMLmactionFrame::MouseClick()
       mContent->SetAttr(kNameSpaceID_None, nsGkAtoms::selection_, value, notify);
 
       // Now trigger a content-changed reflow...
       PresContext()->PresShell()->
         FrameNeedsReflow(mSelectedFrame, nsIPresShell::eTreeChange,
                          NS_FRAME_IS_DIRTY);
     }
   }
-  else if (NS_MATHML_ACTION_TYPE_RESTYLE == mActionType) {
-    if (!mRestyle.IsEmpty()) {
-      nsCOMPtr<nsIDOMElement> node( do_QueryInterface(mContent) );
-      if (node.get()) {
-        if (nsContentUtils::HasNonEmptyAttr(mContent, kNameSpaceID_None,
-                                            nsGkAtoms::actiontype_))
-          node->RemoveAttribute(NS_LITERAL_STRING("actiontype"));
-        else
-          node->SetAttribute(NS_LITERAL_STRING("actiontype"), mRestyle);
-
-        // Trigger a style change reflow
-        PresContext()->PresShell()->
-          FrameNeedsReflow(mSelectedFrame, nsIPresShell::eStyleChange,
-                           NS_FRAME_IS_DIRTY);
-      }
-    }
-  }
 }