added default attribute handling

layout/html/table/src/nsTableCaption.cpp

@@ -86,6 +86,7 @@ void nsTableCaption::SetAttribute(nsIAtom* aAttribute, const nsString& aValue)
     }
     return;
   }
+  nsTableContent::SetAttribute(aAttribute, aValue);
 }
 
 void nsTableCaption::MapAttributesInto(nsIStyleContext* aContext,

layout/html/table/src/nsTableColGroup.cpp

@@ -304,6 +304,7 @@ void nsTableColGroup::SetAttribute(nsIAtom* aAttribute, const nsString& aValue)
     }
     return;
   }
+  nsTableContent::SetAttribute(aAttribute, aValue);
 }
 
 void nsTableColGroup::MapAttributesInto(nsIStyleContext* aContext,

layout/html/table/src/nsTableRow.cpp

@@ -245,6 +245,7 @@ void nsTableRow::SetAttribute(nsIAtom* aAttribute, const nsString& aValue)
     nsHTMLTagContent::SetAttribute(aAttribute, val);
     return;
   }
+  nsTableContent::SetAttribute(aAttribute, aValue);
 }
 
 void nsTableRow::MapAttributesInto(nsIStyleContext* aContext,

layout/html/table/src/nsTableRowGroup.cpp

@@ -93,6 +93,7 @@ void nsTableRowGroup::SetAttribute(nsIAtom* aAttribute, const nsString& aValue)
     nsHTMLTagContent::SetAttribute(aAttribute, val);
     return;
   }
+  nsTableContent::SetAttribute(aAttribute, aValue);
 }
 
 void nsTableRowGroup::MapAttributesInto(nsIStyleContext* aContext,