Added memory usage function to base.

webrtc/base/memory_usage.h

+/*
+ *  Copyright (c) 2017 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.
+ */
+#ifndef WEBRTC_BASE_MEMORY_USAGE_H_
+#define WEBRTC_BASE_MEMORY_USAGE_H_
+
+#include <stdint.h>
+
+namespace rtc {
+
+// Returns current memory used by the process in bytes.

[Taylor Brandstetter, 2017/02/25 00:52:59]

Could you add that this returns -1 on failure, and describe more precisely what
memory size is returned? Would that be "working set size, or resident size on
Linux/Mac"?

[ilnik, 2017/02/27 08:46:16]

Done. Also changed the name of the function to better reflect it's nature.

+int64_t GetProcessMemoryUsageBytes();
+
+}  // namespace rtc
+
+#endif  // WEBRTC_BASE_MEMORY_USAGE_H_