Chrome power profiler service

content/public/browser/power_data_provider.h

+// Copyright 2014 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_PUBLIC_BROWSER_POWER_DATA_PROVIDER_H_
+#define CONTENT_PUBLIC_BROWSER_POWER_DATA_PROVIDER_H_
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
+
+namespace content {
+
+struct PowerEvent {
+  enum Type {
+    // Total power of SoC. including CPU, GT and others on the chip.
+    SOC_PACKAGE,
+
+    // Count the number of known PowerEvent.
+    ID_COUNT
+  };
+
+  Type type;
+  base::TimeTicks time;

[qsr, 2014/01/23 12:50:06]

Comment on those 2 values, especially the |value| one. What is it, what is the
unit.

[Pan, 2014/01/25 09:35:53]

Done.

+  double value;
+};
+
+// a class used to GET power usage.
+class PowerDataProvider {
+ public:
+  PowerDataProvider() { }
+  virtual ~PowerDataProvider() { }
+
+  // Return true when success, it fills a single PowerEvent, which should be
+  // allocated by its caller.
+  virtual bool GetData(PowerEvent*) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PowerDataProvider);
+};
+
+class PowerDataProviderFactory {
+ public:
+  // Create a provider, and transfer the ownship to PowerProfilerService.
+  static scoped_ptr<PowerDataProvider> Create();
+
+ private:
+  PowerDataProviderFactory() { }
+  DISALLOW_COPY_AND_ASSIGN(PowerDataProviderFactory);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_POWER_DATA_PROVIDER_H_