Fix test for HTML image element in V8ClipboardCustom.cpp.

      Use the hasTagName() method, rather than the hasLocalName() method, so that
namespaces are handled properly.

TBR=haraken@chromium.org
BUG=230176

Review URL: https://codereview.chromium.org/14099005

git-svn-id: svn://svn.chromium.org/blink/trunk@148487 bbb929c8-8fbe-4397-9dbb-9b2b20218538