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

components/nacl/zygote/nacl_fork_delegate_linux.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/nacl/zygote/nacl_fork_delegate_linux.h"
 
 #include <signal.h>
 #include <stdlib.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
@@ skipping 92 matching lines @@
 }  // namespace.
 
 NaClForkDelegate::NaClForkDelegate()
     : status_(kNaClHelperUnused),
       fd_(-1) {}
 
 void NaClForkDelegate::Init(const int sandboxdesc) {
   VLOG(1) << "NaClForkDelegate::Init()";
   int fds[2];
 
-  // Confirm a hard-wired assumption.
-  // The NaCl constant is from chrome/nacl/nacl_linux_helper.h
-  DCHECK(kNaClSandboxDescriptor == sandboxdesc);
-
   CHECK(socketpair(PF_UNIX, SOCK_SEQPACKET, 0, fds) == 0);
   base::FileHandleMappingVector fds_to_map;
   fds_to_map.push_back(std::make_pair(fds[1], kNaClZygoteDescriptor));
   fds_to_map.push_back(std::make_pair(sandboxdesc, kNaClSandboxDescriptor));
 
   // Using nacl_helper_bootstrap is not necessary on x86-64 because
   // NaCl's x86-64 sandbox is not zero-address-based.  Starting
   // nacl_helper through nacl_helper_bootstrap works on x86-64, but it
   // leaves nacl_helper_bootstrap mapped at a fixed address at the
   // bottom of the address space, which is undesirable because it
@@ skipping 123 matching lines @@
   if (process_type != switches::kNaClLoaderProcess)
     return false;
   *uma_name = "NaCl.Client.Helper.StateOnFork";
   *uma_sample = status_;
   *uma_boundary_value = kNaClHelperStatusBoundary;
   return status_ == kNaClHelperSuccess;
 }
 
 pid_t NaClForkDelegate::Fork(const std::vector<int>& fds) {
   VLOG(1) << "NaClForkDelegate::Fork";
-
-  DCHECK(fds.size() == kNaClParentFDIndex + 1);
+  DCHECK(fds.size() == kNaClParentFDIndex(fds.size()) + 1);
 
   // First, send a remote fork request.
   Pickle write_pickle;
   write_pickle.WriteInt(kNaClForkRequest);
 
   char reply_buf[kNaClMaxIPCMessageLength];
   ssize_t reply_size = 0;
   bool got_reply =
       SendIPCRequestAndReadReply(fd_, fds, write_pickle,
                                  reply_buf, sizeof(reply_buf), &reply_size);
@@ skipping 60 matching lines @@
   int remote_exit_code;
   if (!iter.ReadInt(&remote_exit_code)) {
     LOG(ERROR) << "GetTerminationStatus: pickle failed";
     return false;
   }
 
   *status = static_cast<base::TerminationStatus>(termination_status);
   *exit_code = remote_exit_code;
   return true;
 }