GlyphMetricsMap should use OwnPtr.
<http://webkit.org/b/111937>

Reviewed by Anders Carlsson.

Use OwnPtr instead of raw pointer + deleteAllValues().

* platform/graphics/GlyphMetricsMap.h:
(GlyphMetricsMap):
(WebCore::::locatePageSlowCase):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145327 268f45cc-cd09-0410-ab3c-d52691b4dbfc