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

src/doc/SkDocument_XPS.cpp

Index: src/doc/SkDocument_XPS.cpp
diff --git a/src/doc/SkDocument_XPS.cpp b/src/doc/SkDocument_XPS.cpp
index 57fa0b80c6014460765e14d83a28ff0a5b55d0c8..0e241d9aaa369974b6a8133b8a166aa61c80be40 100644
--- a/src/doc/SkDocument_XPS.cpp
+++ b/src/doc/SkDocument_XPS.cpp
@@ -5,6 +5,9 @@
  * found in the LICENSE file.
  */
 
+#include "SkTypes.h"
+#if defined(SK_BUILD_FOR_WIN32)
+
 #include "SkDocument.h"
 #include "SkXPSDevice.h"
 #include "SkStream.h"
@@ -75,3 +78,5 @@ SkDocument* SkDocument::CreateXPS(const char path[], SkScalar dpi) {
     }
     return new SkDocument_XPS(stream.detach(), delete_wstream, dpi);
 }
+
+#endif//defined(SK_BUILD_FOR_WIN32)