Pass StatsTable shared memory via global descriptors on Posix rather than using named shared memory.

components/nacl/common/nacl_helper_linux.h

Index: components/nacl/common/nacl_helper_linux.h
diff --git a/components/nacl/common/nacl_helper_linux.h b/components/nacl/common/nacl_helper_linux.h
index a9324b3fa1d786a2cd705bcad2d33cd36b9747ca..9f6c31d665c69a35417ccf3390437b004e52cda3 100644
--- a/components/nacl/common/nacl_helper_linux.h
+++ b/components/nacl/common/nacl_helper_linux.h
@@ -28,10 +28,10 @@ enum NaClZygoteIPCCommand {
 #define kNaClZygoteDescriptor 3
 // For communications between the NaCl loader process and
 // the SUID sandbox.
-#define kNaClSandboxDescriptor 5
+#define kNaClSandboxDescriptor 6
 // NOTE: kNaClSandboxDescriptor must match
-// content/browser/zygote_main_linux.cc
-// kMagicSandboxIPCDescriptor.
+// content/public/common/content_descriptors.h
+// kSandboxIPCChannel + base::GlobalDescriptors::kBaseDescriptor

[Mark Seaborn, 2013/10/14 22:01:50]

Would you mind removing kNaClSandboxDescriptor from this file and changing
components/nacl/zygote/nacl_fork_delegate_linux.cc to use kSandboxIPCChannel +
base::GlobalDescriptors::kBaseDescriptor instead of kNaClSandboxDescriptor?

It's just a small cleanup now, but I think it's better to clean that up than
document that two parts of the code have to be kept in sync manually.

[rmcilroy, 2013/10/15 18:47:50]

Done.

 
 // A fork request from the Zygote to the helper includes an array
 // of three file descriptors. These constants are used as indicies