Remove support for attribute event listeners.

client/dom/generated/src/frog/HTMLInputElement.dart

 
 class HTMLInputElement extends HTMLElement native "HTMLInputElement" {
 
   String accept;
 
   String accessKey;
 
   String align;
 
   String alt;
@@ skipping 35 matching lines @@
   String max;
 
   int maxLength;
 
   String min;
 
   bool multiple;
 
   String name;
 
-  EventListener onwebkitspeechchange;
-
   String pattern;
 
   String placeholder;
 
   bool readOnly;
 
   bool required;
 
   HTMLOptionElement selectedOption;
 
@@ skipping 38 matching lines @@
   void select() native;
 
   void setCustomValidity(String error) native;
 
   void setSelectionRange(int start, int end, [String direction = null]) native;
 
   void stepDown([int n = null]) native;
 
   void stepUp([int n = null]) native;
 }