NaCl: Clean up file descriptor setup in nacl_helper on linux

chrome/common/nacl_helper_linux.h

Index: chrome/common/nacl_helper_linux.h
diff --git a/chrome/common/nacl_helper_linux.h b/chrome/common/nacl_helper_linux.h
index ec12e27df405851c6b088adcc546d9bd756c1e05..0f21895f0e312fc6dc695d8812dbe629543bc490 100644
--- a/chrome/common/nacl_helper_linux.h
+++ b/chrome/common/nacl_helper_linux.h
@@ -18,17 +18,14 @@
 // For communications between NaCl loader and browser.

[jam, 2013/01/10 17:37:50]

nit: should this be removed now?

[Mark Seaborn, 2013/01/10 17:43:19]

No, this comment still applies.  kNaClSandboxDescriptor is used for
communicating with the browser process.

 // See also content/common/zygote_main_linux.cc and
 // http://code.google.com/p/chromium/wiki/LinuxZygote
-#define kNaClBrowserDescriptor 3
+
 // For communications between NaCl loader and zygote.
-// We put the kNaClZygoteDescriptor on 3 together with the
-// kNaClBrowserDescriptor. They are never used at the same
-// time, and this prevents /dev/urandom from using the fd.
 #define kNaClZygoteDescriptor 3
 // For communications between the NaCl loader process and
 // the SUID sandbox.
 #define kNaClSandboxDescriptor 5
-// NOTE: kNaClBrowserDescriptor and kNaClSandboxDescriptor must match
-// content/browser/zygote_main_linux.cc kBrowserDescriptor and
+// NOTE: kNaClSandboxDescriptor must match
+// content/browser/zygote_main_linux.cc
 // kMagicSandboxIPCDescriptor.
 
 // A fork request from the Zygote to the helper includes an array