Remove dependency on dwmapi.dll.

This code hasn't been used by Chrome since it switched to using shared textures for its presentation path on Vista and later.

It will also resolve this:
https://codereview.appspot.com/7816046/
Review URL: https://codereview.appspot.com/7872045

git-svn-id: http://angleproject.googlecode.com/svn/trunk@2002 736b8ea6-26fd-11df-bfd4-992fa37f6226