Android systrace: Optimize memory dumps.

systrace/atrace_helper/jni/procfs_utils.h

+// Copyright 2017 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.
+
+#ifndef PROCFS_UTILS_H_
+#define PROCFS_UTILS_H_
+
+#include <memory>
+#include <string>
+
+#include "process_info.h"
+
+namespace procfs_utils {
+
+// ProcFS doesn't necessarly distinguish PID vs. TID, but all threads of a
+// process have the same Thread Group ID which is equal to Process ID.
+int ReadTgid(int pid);
+
+std::unique_ptr<ProcessInfo> ReadProcessInfo(int pid);
+void ReadProcessThreads(ProcessInfo* process);
+
+bool ReadOomStats(ProcessSnapshot* snapshot);
+bool ReadPageFaultsAndCpuTimeStats(ProcessSnapshot* snapshot);
+
+}  // namespace procfs_utils
+
+#endif  // PROCFS_UTILS_H_