Convert NaCl renderer-browser messages to mojo.

components/nacl/browser/pnacl_host.h

Index: components/nacl/browser/pnacl_host.h
diff --git a/components/nacl/browser/pnacl_host.h b/components/nacl/browser/pnacl_host.h
index ff3f04eba7da6a4ccab6193dfc2c4f89be0830c5..4956d8d1551abd273dc276efa28e7d8cf08b0855 100644
--- a/components/nacl/browser/pnacl_host.h
+++ b/components/nacl/browser/pnacl_host.h
@@ -34,7 +34,7 @@ class PnaclTranslationCache;
 class PnaclHost {
  public:
   typedef base::Callback<void(base::File)> TempFileCallback;
-  typedef base::Callback<void(const base::File&, bool is_hit)> NexeFdCallback;
+  typedef base::Callback<void(base::File, bool is_hit)> NexeFdCallback;
 
   // Gets the PnaclHost singleton instance (creating it if necessary).
   // PnaclHost is a singleton because there is only one translation cache, and
@@ -70,9 +70,6 @@ class PnaclHost {
   // If the cache request was a miss, the caller is expected to call
   // TranslationFinished after it finishes translation to allow the nexe to be
   // stored in the cache.
-  // The returned temp fd may be closed at any time by PnaclHost, so it should
-  // be duplicated (e.g. with IPC::GetPlatformFileForTransit) before the
-  // callback returns.
   // If |is_incognito| is true, the nexe will not be stored
   // in the cache, but the renderer is still expected to call
   // TranslationFinished.