Added --deepColor option to SampleApp, triggers creation of a ten-bit/channel buffer on Windows.

include/views/SkOSWindow_Mac.h

Index: include/views/SkOSWindow_Mac.h
diff --git a/include/views/SkOSWindow_Mac.h b/include/views/SkOSWindow_Mac.h
index efa97bf87245c35ba9c873a8f3987836c2f7aa30..fd26fec0690892f5bd7e4e931be5162b67512865 100644
--- a/include/views/SkOSWindow_Mac.h
+++ b/include/views/SkOSWindow_Mac.h
@@ -33,7 +33,8 @@ public:
     };
 
     void    release();
-    bool    attach(SkBackEndTypes attachType, int msaaSampleCount, AttachmentInfo*);
+    bool    attach(SkBackEndTypes attachType, int msaaSampleCount, bool tenBitColor,
+                   AttachmentInfo*);
     void    present();
 
     bool    makeFullscreen();