Implementation of dwrite font proxy and removal of dwrite font cache

ui/gfx/win/direct_write.h

Index: ui/gfx/win/direct_write.h
diff --git a/ui/gfx/win/direct_write.h b/ui/gfx/win/direct_write.h
index f16e45c31410c09891f9f7b6e5359f9a8863c7b2..1fa268d87d22c3fb1023c2d6d189e145f97976bc 100644
--- a/ui/gfx/win/direct_write.h
+++ b/ui/gfx/win/direct_write.h
@@ -5,6 +5,8 @@
 #ifndef UI_GFX_WIN_DIRECT_WRITE_H_
 #define UI_GFX_WIN_DIRECT_WRITE_H_
 
+#include <dwrite.h>
+
 #include "ui/gfx/gfx_export.h"
 
 namespace gfx {
@@ -18,6 +20,9 @@ GFX_EXPORT void MaybeInitializeDirectWrite();
 // Returns true if we are using DirectWrite for font metrics and rendering.
 GFX_EXPORT bool IsDirectWriteEnabled();
 
+// Returns the direct write factory, if using direct write, or null otherwise.
+GFX_EXPORT void GetDWriteFactory(IDWriteFactory** factory);
+
 }  // namespace win
 }  // namespace gfx