build: More build fixes and cleanups

webrtc/system_wrappers/source/rw_lock.cc

@@ -0,0 +1,37 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/system_wrappers/interface/rw_lock_wrapper.h"
+
+#include <assert.h>
+
+#if defined(_WIN32)
+#include "webrtc/system_wrappers/source/rw_lock_generic.h"
+#include "webrtc/system_wrappers/source/rw_lock_win.h"
+#else
+#include "webrtc/system_wrappers/source/rw_lock_posix.h"
+#endif
+
+namespace webrtc {
+
+RWLockWrapper* RWLockWrapper::CreateRWLock() {
+#ifdef _WIN32
+  // Native implementation is faster, so use that if available.
+  RWLockWrapper* lock = RWLockWin::Create();
+  if (lock) {
+    return lock;
+  }
+  return new RWLockGeneric();
+#else
+  return RWLockPosix::Create();
+#endif
+}
+
+}  // namespace webrtc