Use RecvMsgWithPid to find zygote PID instead of chrome-sandbox

content/zygote/zygote_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 "content/zygote/zygote_linux.h"
 
 #include <fcntl.h>
 #include <string.h>
 #include <sys/socket.h>
 #include <sys/types.h>
@@ skipping 65 matching lines @@
   // We need to accept SIGCHLD, even though our handler is a no-op because
   // otherwise we cannot wait on children. (According to POSIX 2001.)
   struct sigaction action;
   memset(&action, 0, sizeof(action));
   action.sa_handler = &SIGCHLDHandler;
   CHECK(sigaction(SIGCHLD, &action, NULL) == 0);
 
   if (UsingSUIDSandbox()) {
     // Let the ZygoteHost know we are ready to go.
     // The receiving code is in content/browser/zygote_host_linux.cc.
-    std::vector<int> empty;
     bool r = UnixDomainSocket::SendMsg(kZygoteSocketPairFd,
                                        kZygoteHelloMessage,
-                                       sizeof(kZygoteHelloMessage), empty);
+                                       sizeof(kZygoteHelloMessage),
+                                       std::vector<int>());
 #if defined(OS_CHROMEOS)
     LOG_IF(WARNING, !r) << "Sending zygote magic failed";
     // Exit normally on chromeos because session manager may send SIGTERM
     // right after the process starts and it may fail to send zygote magic
     // number to browser process.
     if (!r)
       _exit(RESULT_CODE_NORMAL_EXIT);
 #else
     CHECK(r) << "Sending zygote magic failed";
 #endif
@@ skipping 382 matching lines @@
       static_cast<uint32_t>(kSandboxIPCChannel), GetSandboxFD()));
 
   // Returns twice, once per process.
   base::ProcessId child_pid = ForkWithRealPid(process_type, mapping, channel_id,
                                               uma_name, uma_sample,
                                               uma_boundary_value);
   if (!child_pid) {
     // This is the child process.
 
     close(kZygoteSocketPairFd);  // Our socket from the browser.
-    if (UsingSUIDSandbox())
-      close(kZygoteIdFd);  // Another socket from the browser.
     base::GlobalDescriptors::GetInstance()->Reset(mapping);
 
     // Reset the process-wide command line to our new command line.
     CommandLine::Reset();
     CommandLine::Init(0, NULL);
     CommandLine::ForCurrentProcess()->InitFromArgv(args);
 
     // Update the process title. The argv was already cached by the call to
     // SetProcessTitleFromCommandLine in ChromeMain, so we can pass NULL here
     // (we don't have the original argv at this point).
@@ skipping 48 matching lines @@
                                     PickleIterator iter) {
   if (HANDLE_EINTR(write(fd, &sandbox_flags_, sizeof(sandbox_flags_))) !=
                    sizeof(sandbox_flags_)) {
     PLOG(ERROR) << "write";
   }
 
   return false;
 }
 
 }  // namespace content