This tests single-clicking on an image inside user-select: all. WebKit should select the entire element.
Firefox doesn't do this but I'm not sure it makes sense for us to be inconsistent since Firefox DOES allow text with user-select: all to be selected by a single click.
To manually test, single click on the image below. WebKit should select the entire bordered region.
| <div>
|   class="select-all"
|   <#selection-anchor>
|   <img>
|     src="../resources/abe.png"
|   <#selection-focus>