TSANv2: disable non sandbox-related threading checks under TSAN.

content/zygote/zygote_main_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_main.h"
 
 #include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <pthread.h>
@@ skipping 314 matching lines @@
 
   sandbox::SetuidSandboxClient* setuid_sandbox =
       linux_sandbox->setuid_sandbox_client();
 
   if (!setuid_sandbox)
     return false;
 
   PreSandboxInit();
 
   // Check that the pre-sandbox initialization didn't spawn threads.
+#if !defined(THREAD_SANITIZER)
   DCHECK(linux_sandbox->IsSingleThreaded());
+#endif
 
   if (setuid_sandbox->IsSuidSandboxChild()) {
     // Use the SUID sandbox.  This still allows the seccomp sandbox to
     // be enabled by the process later.
     *using_suid_sandbox = true;
 
     if (!setuid_sandbox->IsSuidSandboxUpToDate()) {
       LOG(WARNING) << "You are using a wrong version of the setuid binary!\n"
        "Please read "
        "https://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment."
@@ skipping 89 matching lines @@
   }
 
   int sandbox_flags = linux_sandbox->GetStatus();
 
   Zygote zygote(sandbox_flags, forkdelegate);
   // This function call can return multiple times, once per fork().
   return zygote.ProcessRequests();
 }
 
 }  // namespace content