Where is the content of the pop up bubble in my form validation coming from?
In our instance we used clumsyfingers's code but with parsing fix:

novalidate cannot be "1". It has to be either: 


no value
empty value
value = attribute name


like so: 

function mymodule_form_alter(&amp;$form,&amp;$form_state,$form_id) {

  if(strstr($form_id,'webform') !== FALSE) {  
    // prevent html5 validation, i.e. on input type="email" fields  
    form['#attributes']['novalidate'] = 'novalidate';  
  }

}


CSE HTML validator was returning this message:


  The "novalidate" attribute for the "form" element has an invalid value
  "1". This is a boolean (true or false) attribute. The presence of a
  boolean attribute represents true and absense of the attribute
  represents false. Setting a value is not necessary, but if a value is
  set, then it must be an empty string or be a case-insensitive match
  for the attribute's name. NOTE: Never use the values "true" and
  "false".