tipAttribute is not working properly

[ebidel]

From @saan1984 on January 26, 2015 14:39

tipAttribute is not working when it takes value other then htmlooltip.
For example,

<core-tooltip tipAttribute="abcd">
  <div>Example of a rich information tooltip</div>
  <div abcd>
       ...
  </div>
</core-tooltip>

Copied from original issue: Polymer/polymer#1126