CSS generated content without space goes missing (Safari)

[ebidel]

Test: http://jsbin.com/arOtOpU/2/edit

Under the SD polyfill, CSS generated content (without whitespace?) gets dropped on the floor in Safari Version 7.0.1 (9537.73.11).

<polymer-element name="ui-icon" noscript>
  <template>
    <style>
      :host {
        display: block;
      }
      #one::before {
        content: "hi there";
      }
      #two::before {
        content: "hithere"; / * doesn't work no space */
      }
      #three::before {
        content: " hi there"; / * works */
      }
      #four::before {
        content: "hithere "; / * works */
      }
    </style>
    <div id="one">1</div>
    <div id="two">2</div>
    <div id="three">3</div>
    <div id="four">4</div>
  </template>
</polymer-element>

The first rule ends up as content: hithere (note the missing quotes) in the inspector:

Note: the jsbin works correctly in FF and Chrome under the polyfill. The bin also works outside of the SD (http://jsbin.com/iQopEjeW/1/edit).