Start making all .cpp files compile-able on all platforms.

src/utils/win/SkDWrite.cpp

Index: src/utils/win/SkDWrite.cpp
diff --git a/src/utils/win/SkDWrite.cpp b/src/utils/win/SkDWrite.cpp
index 2254961d146cb1f5f80d20be0d2606a2377f995f..2fdd6115b00d9cd5b5aca80fab1f9cf149a9661e 100644
--- a/src/utils/win/SkDWrite.cpp
+++ b/src/utils/win/SkDWrite.cpp
@@ -4,6 +4,8 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+#include "SkTypes.h"
+#if defined(SK_BUILD_FOR_WIN32)
 
 #include "SkDWrite.h"
 #include "SkHRESULT.h"
@@ -122,3 +124,5 @@ HRESULT SkGetGetUserDefaultLocaleNameProc(SkGetUserDefaultLocaleNameProc* proc)
     }
     return S_OK;
 }
+
+#endif//defined(SK_BUILD_FOR_WIN32)