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

src/gpu/gl/mac/GrGLCreateNativeInterface_mac.cpp

Index: src/gpu/gl/mac/GrGLCreateNativeInterface_mac.cpp
diff --git a/src/gpu/gl/mac/GrGLCreateNativeInterface_mac.cpp b/src/gpu/gl/mac/GrGLCreateNativeInterface_mac.cpp
index 9a2abfe06657e657b58820eecc4975f3ea6bef7c..83e559339a251a345779cb666a1f39ff3b84b845 100644
--- a/src/gpu/gl/mac/GrGLCreateNativeInterface_mac.cpp
+++ b/src/gpu/gl/mac/GrGLCreateNativeInterface_mac.cpp
@@ -5,6 +5,8 @@
  * 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_MAC)
 
 
 #include "gl/GrGLInterface.h"
@@ -56,3 +58,5 @@ const GrGLInterface* GrGLCreateNativeInterface() {
     GLProcGetter getter;
     return GrGLAssembleGLInterface(&getter, mac_get_gl_proc);
 }
+
+#endif//defined(SK_BUILD_FOR_MAC)