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

native_client_sdk/src/libraries/nacl_io/kernel_proxy.h

Index: native_client_sdk/src/libraries/nacl_io/kernel_proxy.h
diff --git a/native_client_sdk/src/libraries/nacl_io/kernel_proxy.h b/native_client_sdk/src/libraries/nacl_io/kernel_proxy.h
index 046d92267a7d7abdd060250a326e0f94c1ff1b53..e3ea442d79f4fcc902d0eec736e661bf4367018d 100644
--- a/native_client_sdk/src/libraries/nacl_io/kernel_proxy.h
+++ b/native_client_sdk/src/libraries/nacl_io/kernel_proxy.h
@@ -67,7 +67,7 @@ class KernelProxy : protected KernelObject {
   virtual int open_resource(const char* file);
 
   // KernelHandle and FD allocation and manipulation functions.
-  virtual int open(const char* path, int open_flags);
+  virtual int open(const char* path, int open_flags, mode_t mode_flags);
   virtual int close(int fd);
   virtual int dup(int fd);
   virtual int dup2(int fd, int newfd);