Fix cross compilation with mingw.

Mingw is case sensitive, so use the correct capitaliztion of dwrite.h.
https://codereview.appspot.com/6588055

Props jacek.


git-svn-id: http://skia.googlecode.com/svn/trunk@6197 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed