Use a global ref-counted singleton for long name map. This makes sure the same varying/uniform variables maps to the unique name in vertex/fragment shader. BUG= TEST=webgl conformance tests Review URL: https://codereview.appspot.com/5556065 git-svn-id: https://angleproject.googlecode.com/svn/trunk@950 736b8ea6-26fd-11df-bfd4-992fa37f6226