Ignore usemap attributes without '#' in img element
https://bugs.webkit.org/show_bug.cgi?id=133336

Reviewed by Ryosuke Niwa.

HTML5 specification says we should ignore usemap attributes without #.
http://www.w3.org/TR/html5/infrastructure.html#valid-hash-name-reference

Source/WebCore:

Test: fast/dom/replaced-image-map-valid-hash-name.html

* dom/TreeScope.cpp:
(WebCore::TreeScope::getImageMap):

LayoutTests:

* fast/dom/replaced-image-map-valid-hash-name-expected.txt: Added.
* fast/dom/replaced-image-map-valid-hash-name.html: Added.
* fast/images/image-map-multiple-xhtml.xhtml: Modified usemap attribute value to use '#'.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@172796 268f45cc-cd09-0410-ab3c-d52691b4dbfc