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

src/utils/mac/SkStream_mac.cpp

Index: src/utils/mac/SkStream_mac.cpp
diff --git a/src/utils/mac/SkStream_mac.cpp b/src/utils/mac/SkStream_mac.cpp
index e62ced220fabace1b8b45a72c39b7b4e035e1fa3..36e5194a1990b3e65bdbf0fe3654bcff5659b167 100644
--- a/src/utils/mac/SkStream_mac.cpp
+++ b/src/utils/mac/SkStream_mac.cpp
@@ -5,6 +5,9 @@
  * found in the LICENSE file.
  */
 
+#include "SkTypes.h"
+#if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
+
 #include "SkCGUtils.h"
 #include "SkStream.h"
 
@@ -74,3 +77,5 @@ CGDataProviderRef SkCreateDataProviderFromData(SkData* data) {
     return CGDataProviderCreateWithData(data, data->data(), data->size(),
                                             unref_proc);
 }
+
+#endif//defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)