AdjustRendererOOMScore isn't execute in linux.

content/browser/zygote_host/zygote_host_impl_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/browser/zygote_host/zygote_host_impl_linux.h"
 
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ skipping 415 matching lines @@
     if (IsHeapProfilerRunning())
       return;
 #endif
     std::vector<std::string> adj_oom_score_cmdline;
     adj_oom_score_cmdline.push_back(sandbox_binary_);
     adj_oom_score_cmdline.push_back(sandbox::kAdjustOOMScoreSwitch);
     adj_oom_score_cmdline.push_back(base::Int64ToString(pid));
     adj_oom_score_cmdline.push_back(base::IntToString(score));
 
     base::ProcessHandle sandbox_helper_process;
-    if (base::LaunchProcess(adj_oom_score_cmdline, base::LaunchOptions(),
+    base::LaunchOptions options;
+    options.allow_new_privs = true;

[jln (very slow on Chromium), 2014/04/24 00:17:59]

Please add a comment along the lines of "sandbox_helper_process is a setuid
binary".

+    if (base::LaunchProcess(adj_oom_score_cmdline, options,
                             &sandbox_helper_process)) {
       base::EnsureProcessGetsReaped(sandbox_helper_process);
     }
   } else if (!using_suid_sandbox_) {
     if (!base::AdjustOOMScore(pid, score))
       PLOG(ERROR) << "Failed to adjust OOM score of renderer with pid " << pid;
   }
 }
 #endif
 
@@ skipping 51 matching lines @@
       status = tmp_status;
     }
   }
 
   if (status != base::TERMINATION_STATUS_STILL_RUNNING) {
     ZygoteChildDied(handle);
   }
   return static_cast<base::TerminationStatus>(status);
 }
 
+bool ZygoteHostImpl::UsingSUIDSandbox() const {
+  return using_suid_sandbox_;
+}
+
 pid_t ZygoteHostImpl::GetPid() const {
   return pid_;
 }
 
 pid_t ZygoteHostImpl::GetSandboxHelperPid() const {
   return RenderSandboxHostLinux::GetInstance()->pid();
 }
 
 int ZygoteHostImpl::GetSandboxStatus() const {
   if (have_read_sandbox_status_word_)
     return sandbox_status_;
   return 0;
 }
 
 }  // namespace content