Plumbing though mode parameter to open, since fusefs can make use of it.

native_client_sdk/src/libraries/nacl_io/jsfs/js_fs.h

Index: native_client_sdk/src/libraries/nacl_io/jsfs/js_fs.h
diff --git a/native_client_sdk/src/libraries/nacl_io/jsfs/js_fs.h b/native_client_sdk/src/libraries/nacl_io/jsfs/js_fs.h
index 901ac574a8bd3658efb4779ef3f8b8a1376c29cb..08b1e4c182f805de7c0b49f66d63b3efcd09909d 100644
--- a/native_client_sdk/src/libraries/nacl_io/jsfs/js_fs.h
+++ b/native_client_sdk/src/libraries/nacl_io/jsfs/js_fs.h
@@ -35,7 +35,8 @@ class JsFs : public Filesystem {
   virtual void Destroy();
 
  public:
-  virtual Error Open(const Path& path, int mode, ScopedNode* out_node);
+  virtual Error OpenWithMode(const Path& path, int open_flags, mode_t mode,
+                             ScopedNode* out_node);
   virtual Error Unlink(const Path& path);
   virtual Error Mkdir(const Path& path, int perm);
   virtual Error Rmdir(const Path& path);