diff -r 000000000000 -r 6474c204b198 security/sandbox/chromium/base/synchronization/lock_impl_win.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/security/sandbox/chromium/base/synchronization/lock_impl_win.cc	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+// Copyright (c) 2011 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 "base/synchronization/lock_impl.h"
+
+namespace base {
+namespace internal {
+
+LockImpl::LockImpl() {
+  // The second parameter is the spin count, for short-held locks it avoid the
+  // contending thread from going to sleep which helps performance greatly.
+  ::InitializeCriticalSectionAndSpinCount(&native_handle_, 2000);
+}
+
+LockImpl::~LockImpl() {
+  ::DeleteCriticalSection(&native_handle_);
+}
+
+bool LockImpl::Try() {
+  if (::TryEnterCriticalSection(&native_handle_) != FALSE) {
+    return true;
+  }
+  return false;
+}
+
+void LockImpl::Lock() {
+  ::EnterCriticalSection(&native_handle_);
+}
+
+void LockImpl::Unlock() {
+  ::LeaveCriticalSection(&native_handle_);
+}
+
+}  // namespace internal
+}  // namespace base