[giow] (2) Allow <input type=file> to be reset by setting value to ''.

git-svn-id: http://svn.whatwg.org/webapps@3874 340c8d12-0b0e-0410-8428-c7bf67bfef74

index

 
    <dd>On getting, it must return the string "<code title="">C:\fakepath\</code>" followed by the filename of the first
    file in the list of <a href=#concept-input-type-file-selected title=concept-input-type-file-selected>selected files</a>, if
-   any, or the empty string if the list is empty. On setting, it must
-   throw an <code><a href=#invalid_access_err>INVALID_ACCESS_ERR</a></code> exception.</dd>
+   any, or the empty string if the list is empty. On setting, if the
+   new value is the empty string, it must empty the list of <a href=#concept-input-type-file-selected title=concept-input-type-file-selected>selected files</a>;
+   otherwise, it must throw an <code><a href=#invalid_access_err>INVALID_ACCESS_ERR</a></code>
+   exception.</dd>
 
   </dl><hr><p>The <dfn id=dom-input-checked title=dom-input-checked><code>checked</code></dfn> IDL
   attribute allows scripts to manipulate the <a href=#concept-fe-checked title=concept-fe-checked>checkedness</a> of an

source

    title="">C:\fakepath\</code>" followed by the filename of the first
    file in the list of <span
    title="concept-input-type-file-selected">selected files</span>, if
-   any, or the empty string if the list is empty. On setting, it must
-   throw an <code>INVALID_ACCESS_ERR</code> exception.</dd>
+   any, or the empty string if the list is empty. On setting, if the
+   new value is the empty string, it must empty the list of <span
+   title="concept-input-type-file-selected">selected files</span>;
+   otherwise, it must throw an <code>INVALID_ACCESS_ERR</code>
+   exception.</dd>
 
   </dl>