[tracing] Add a dump provider to dump process memory totals.

base/trace_event/process_memory_totals_dump_provider.h

+// Copyright 2015 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 BASE_TRACE_EVENT_PROCESS_MEMORY_TOTALS_DUMP_PROVIDER_H_
+#define BASE_TRACE_EVENT_PROCESS_MEMORY_TOTALS_DUMP_PROVIDER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
+#include "base/trace_event/memory_dump_provider.h"
+
+namespace base {
+
+class ProcessMetrics;
+
+namespace trace_event {
+
+// Dump provider which collects process-wide memory stats.
+class BASE_EXPORT ProcessMemoryTotalsDumpProvider : public MemoryDumpProvider {
+ public:
+  static ProcessMemoryTotalsDumpProvider* GetInstance();
+
+  // MemoryDumpProvider implementation.
+  void DumpInto(ProcessMemoryDump* pmd) override;
+
+ private:
+  friend struct DefaultSingletonTraits<ProcessMemoryTotalsDumpProvider>;
+
+  ProcessMemoryTotalsDumpProvider();
+  ~ProcessMemoryTotalsDumpProvider() override;
+
+  scoped_ptr<ProcessMetrics> process_metrics_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProcessMemoryTotalsDumpProvider);
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_PROCESS_MEMORY_TOTALS_DUMP_PROVIDER_H_