Architecture for cross-process memory notification suppressing

content/browser/memory/memory_pressure_controller.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 CONTENT_BROWSER_MEMORY_MEMORY_PRESSURE_CONTROLLER_H_
+#define CONTENT_BROWSER_MEMORY_MEMORY_PRESSURE_CONTROLLER_H_
+
+#include <set>
+
+#include "base/callback.h"
+#include "base/memory/singleton.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+class MemoryMessageFilter;
+
+class CONTENT_EXPORT MemoryPressureController {
+ public:
+  // These methods must be called on the IO thread.
+  void OnMemoryMessageFilterAdded(MemoryMessageFilter* filter);
+  void OnMemoryMessageFilterRemoved(MemoryMessageFilter* filter);
+
+  // This method can be called from any thread.
+  void SetPressureNotificationsSuppressedInAllProcesses(bool suppressed);
+
+  // This method can be called from any thread.
+  static MemoryPressureController* GetInstance();
+
+ protected:
+  virtual ~MemoryPressureController();
+
+ private:
+  friend struct base::DefaultSingletonTraits<MemoryPressureController>;
+
+  MemoryPressureController();
+
+  // Set of all memory message filters in the browser process. Always accessed
+  // on the IO thread.
+  typedef std::set<scoped_refptr<MemoryMessageFilter>> MemoryMessageFilterSet;
+  MemoryMessageFilterSet memory_message_filters_;
+
+  DISALLOW_COPY_AND_ASSIGN(MemoryPressureController);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_MEMORY_MEMORY_PRESSURE_CONTROLLER_H_