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

native_client_sdk/src/libraries/nacl_io/html5fs/html5_fs.h

Index: native_client_sdk/src/libraries/nacl_io/html5fs/html5_fs.h
diff --git a/native_client_sdk/src/libraries/nacl_io/html5fs/html5_fs.h b/native_client_sdk/src/libraries/nacl_io/html5fs/html5_fs.h
index 40bc31416502d3ae64424ce340ab091813efe36c..bf4c249a5590ea130eaf509667c0366f966e3715 100644
--- a/native_client_sdk/src/libraries/nacl_io/html5fs/html5_fs.h
+++ b/native_client_sdk/src/libraries/nacl_io/html5fs/html5_fs.h
@@ -18,7 +18,8 @@ class Node;
 
 class Html5Fs : public Filesystem {
  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 permissions);
   virtual Error Rmdir(const Path& path);