Make a NaClDesc ctor for creating descs from NaClFileInfo.

src/trusted/desc/nacl_desc_wrapper.cc

Index: src/trusted/desc/nacl_desc_wrapper.cc
diff --git a/src/trusted/desc/nacl_desc_wrapper.cc b/src/trusted/desc/nacl_desc_wrapper.cc
index ada9cb3aad152810f52670b829e4925ed1652c11..10834a78b1d644824571576a2b1642b3c24be53a 100644
--- a/src/trusted/desc/nacl_desc_wrapper.cc
+++ b/src/trusted/desc/nacl_desc_wrapper.cc
@@ -16,6 +16,7 @@
 #endif  // defined(NACL_LINUX)
 #include "native_client/src/trusted/desc/nacl_desc_base.h"
 #include "native_client/src/trusted/desc/nacl_desc_conn_cap.h"
+#include "native_client/src/trusted/desc/nacl_desc_file_info.h"
 #include "native_client/src/trusted/desc/nacl_desc_imc.h"
 #include "native_client/src/trusted/desc/nacl_desc_imc_shm.h"
 #include "native_client/src/trusted/desc/nacl_desc_invalid.h"
@@ -315,6 +316,15 @@ DescWrapper* DescWrapperFactory::MakeFileDesc(int host_os_desc, int mode) {
   return MakeGenericCleanup(desc);
 }
 
+DescWrapper* DescWrapperFactory::MakeFileDescFileInfo(struct NaClFileInfo info,

[Mark Seaborn, 2014/05/15 00:36:10]

Since DescWrapper is deprecated, can you avoid adding more interface surface to
it, please?  Can you have the Chromium-side code call NaClDescIoFromFileInfo() +
MakeGenericCleanup() instead of adding this method?

[jvoung (off chromium), 2014/05/16 18:02:05]

Okay. The intention was to have a single call that hands off the info's desc and
metadata, and that should still work with NaClDescIoFromFileInfo.

+                                                      int mode) {
+  struct NaClDesc* desc = NaClDescIoFromFileInfo(info, mode);
+  if (NULL == desc) {
+    return NULL;
+  }
+  return MakeGenericCleanup(desc);
+}
+
 DescWrapper* DescWrapperFactory::MakeFileDescQuota(int host_os_desc,
                                                    int mode,
                                                    const uint8_t* file_id) {