cros: Remove unused low memory margin code from sandbox and zygote

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 389 matching lines @@
                             &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
 
-void ZygoteHostImpl::AdjustLowMemoryMargin(int64 margin_mb) {
-#if defined(OS_CHROMEOS)
-  // You can't change the low memory margin unless you're root. Because of this,
-  // we can't set the low memory margin from the browser process.
-  // So, we use the SUID binary to change it for us.
-  if (using_suid_sandbox_) {
-#if defined(USE_TCMALLOC)
-    // If heap profiling is running, these processes are not exiting, at least
-    // on ChromeOS. The easiest thing to do is not launch them when profiling.
-    // TODO(stevenjb): Investigate further and fix.
-    if (IsHeapProfilerRunning())
-      return;
-#endif
-    std::vector<std::string> adj_low_mem_commandline;
-    adj_low_mem_commandline.push_back(sandbox_binary_);
-    adj_low_mem_commandline.push_back(sandbox::kAdjustLowMemMarginSwitch);
-    adj_low_mem_commandline.push_back(base::Int64ToString(margin_mb));
-
-    base::ProcessHandle sandbox_helper_process;
-    if (base::LaunchProcess(adj_low_mem_commandline, base::LaunchOptions(),
-                            &sandbox_helper_process)) {
-      base::EnsureProcessGetsReaped(sandbox_helper_process);
-    } else {
-      LOG(ERROR) << "Unable to run suid sandbox to set low memory margin.";
-    }
-  }
-  // Don't adjust memory margin if we're not running with the sandbox: this
-  // isn't very common, and not doing it has little impact.
-#else
-  // Low memory notification is currently only implemented on ChromeOS.
-  NOTREACHED() << "AdjustLowMemoryMargin not implemented";
-#endif  // defined(OS_CHROMEOS)
-}
-
-
 void ZygoteHostImpl::EnsureProcessTerminated(pid_t process) {
   DCHECK(init_);
   Pickle pickle;
 
   pickle.WriteInt(kZygoteCommandReap);
   pickle.WriteInt(process);
   if (!SendMessage(pickle, NULL))
     LOG(ERROR) << "Failed to send Reap message to zygote";
 }
 
@@ skipping 52 matching lines @@
   return RenderSandboxHostLinux::GetInstance()->pid();
 }
 
 int ZygoteHostImpl::GetSandboxStatus() const {
   if (have_read_sandbox_status_word_)
     return sandbox_status_;
   return 0;
 }
 
 }  // namespace content