Add definition of GlyphBufferGlyph for BlackBerry
https://bugs.webkit.org/show_bug.cgi?id=115183

Patch by Alberto Garcia <agarcia@igalia.com> on 2013-04-25
Reviewed by Xan Lopez.

BlackBerry uses an unsigned int.

* platform/graphics/GlyphBuffer.h:
(WebCore):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149138 268f45cc-cd09-0410-ab3c-d52691b4dbfc