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

ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_shim.c

Index: ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_shim.c
diff --git a/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_shim.c b/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_shim.c
index ec358bf05316bdf9bfde5d044689652be9c6ab1b..afa041357f4fdbdbeaf07341805caebe8acad6b2 100644
--- a/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_shim.c
+++ b/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_shim.c
@@ -2768,6 +2768,11 @@ static int32_t Pnacl_M13_PPB_NaCl_Private_BrokerDuplicateHandle(PP_FileHandle so
   return iface->BrokerDuplicateHandle(source_handle, process_id, target_handle, desired_access, options);
 }
 
+static int32_t Pnacl_M13_PPB_NaCl_Private_EnsurePnaclInstalled(PP_Instance instance, struct PP_CompletionCallback* callback) {
+  const struct PPB_NaCl_Private_1_0 *iface = Pnacl_WrapperInfo_PPB_NaCl_Private_1_0.real_iface;
+  return iface->EnsurePnaclInstalled(instance, *callback);
+}
+
 static PP_FileHandle Pnacl_M13_PPB_NaCl_Private_GetReadonlyPnaclFd(const char* filename) {
   const struct PPB_NaCl_Private_1_0 *iface = Pnacl_WrapperInfo_PPB_NaCl_Private_1_0.real_iface;
   return iface->GetReadonlyPnaclFd(filename);
@@ -4572,6 +4577,7 @@ struct PPB_NaCl_Private_1_0 Pnacl_Wrappers_PPB_NaCl_Private_1_0 = {
     .UrandomFD = (int32_t (*)(void))&Pnacl_M13_PPB_NaCl_Private_UrandomFD,
     .Are3DInterfacesDisabled = (PP_Bool (*)(void))&Pnacl_M13_PPB_NaCl_Private_Are3DInterfacesDisabled,
     .BrokerDuplicateHandle = (int32_t (*)(PP_FileHandle source_handle, uint32_t process_id, PP_FileHandle* target_handle, uint32_t desired_access, uint32_t options))&Pnacl_M13_PPB_NaCl_Private_BrokerDuplicateHandle,
+    .EnsurePnaclInstalled = (int32_t (*)(PP_Instance instance, struct PP_CompletionCallback callback))&Pnacl_M13_PPB_NaCl_Private_EnsurePnaclInstalled,
     .GetReadonlyPnaclFd = (PP_FileHandle (*)(const char* filename))&Pnacl_M13_PPB_NaCl_Private_GetReadonlyPnaclFd,
     .CreateTemporaryFile = (PP_FileHandle (*)(PP_Instance instance))&Pnacl_M13_PPB_NaCl_Private_CreateTemporaryFile,
     .GetNexeFd = (int32_t (*)(PP_Instance instance, const char* pexe_url, uint32_t abi_version, uint32_t opt_level, const char* last_modified, const char* etag, PP_Bool* is_hit, PP_FileHandle* nexe_handle, struct PP_CompletionCallback callback))&Pnacl_M13_PPB_NaCl_Private_GetNexeFd,