[NaCl SDK] Add comments in the implementation code of GoogleDriveFs

native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs.h

Index: native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs.h
diff --git a/native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs.h b/native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs.h
index 179cb8d227c927ea7a8b2660df2b6172fdd84715..fc38652b340b75fc9e5b1f4e1cababba125dbefd 100644
--- a/native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs.h
+++ b/native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs.h
@@ -12,6 +12,10 @@
 
 namespace nacl_io {
 
+// This is not further implemented.
+// PNaCl is on a path to deprecation, and WebAssembly is
+// the focused technology.
+
 class GoogleDriveFs : public Filesystem {
  protected:
   GoogleDriveFs();