PNaCl on-demand installs: Make a separate async IPC to check if PNaCl is installed

ppapi/c/private/ppb_nacl_private.h

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-/* From private/ppb_nacl_private.idl modified Mon Jul 15 09:19:33 2013. */
+/* From private/ppb_nacl_private.idl modified Fri Jul 19 09:51:16 2013. */
 
 #ifndef PPAPI_C_PRIVATE_PPB_NACL_PRIVATE_H_
 #define PPAPI_C_PRIVATE_PPB_NACL_PRIVATE_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_stdint.h"
 #include "ppapi/c/pp_var.h"
@@ skipping 90 matching lines @@
    * use inside the Windows sandbox.  Note that we provide this via dependency
    * injection only to avoid the linkage problems that occur because the NaCl
    * plugin is built as a separate DLL/DSO
    * (see http://code.google.com/p/chromium/issues/detail?id=114439#c8).
    */
   int32_t (*BrokerDuplicateHandle)(PP_FileHandle source_handle,
                                    uint32_t process_id,
                                    PP_FileHandle* target_handle,
                                    uint32_t desired_access,
                                    uint32_t options);
+  /* Check if PNaCl is installed and attempt to install if necessary.
+   * Callback is called when the check is done and PNaCl is already installed,
+   * or after an on-demand install is attempted. Called back with PP_OK is
+   * PNaCl is available. Called back with an error otherwise.
+   */
+  int32_t (*EnsurePnaclInstalled)(PP_Instance instance,
+                                  struct PP_CompletionCallback callback);
   /* Returns a read-only file descriptor of a file rooted in the Pnacl
    * component directory, or an invalid handle on failure.
-   * Do we want this to take a completion callback and be async, or
-   * could we make this happen on another thread?
    */
   PP_FileHandle (*GetReadonlyPnaclFd)(const char* filename);
   /* This creates a temporary file that will be deleted by the time
    * the last handle is closed (or earlier on POSIX systems), and
    * returns a posix handle to that temporary file.
    */
   PP_FileHandle (*CreateTemporaryFile)(PP_Instance instance);
   /* Create a temporary file, which will be deleted by the time the last
    * handle is closed (or earlier on POSIX systems), to use for the nexe
    * with the cache information given by |pexe_url|, |abi_version|, |opt_level|,
@@ skipping 43 matching lines @@
                                       uint64_t* file_token_hi);
 };
 
 typedef struct PPB_NaCl_Private_1_0 PPB_NaCl_Private;
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_PRIVATE_PPB_NACL_PRIVATE_H_ */