Chrome power profiler service

content/browser/power_profiler/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_BROWSER_POWER_PROFILER_POWER_DATA_PROVIDER_H_
+#define CONTENT_BROWSER_POWER_PROFILER_POWER_DATA_PROVIDER_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/time/time.h"
+
+namespace content {
+
+struct PowerEvent {
+  enum Type {
+    // Total power of SoC. including CPU, GT and others on the chip,
+    // modules out of SoC such as screen is not included.

[jeremy, 2014/02/16 14:09:19]

nit: modules which aren't part of the SoC such as the screen are not included.

[Pan, 2014/02/17 03:17:15]

Done.

+    SOC_PACKAGE,
+
+    // Whole device power.
+    DEVICE,
+
+    // Count the number of known PowerEvent.

[jeremy, 2014/02/16 14:09:19]

nit: // Keep this at the end.

[Pan, 2014/02/17 03:17:15]

Done.

+    ID_COUNT
+  };
+
+  Type type;
+
+  base::TimeTicks time; // Time that power data was read.
+
+  // Power value between last event to this one, in watt.
+  // E.g, event1 {t1, v1}; event2 {t2, v2}; event3 {t3, v3}.
+  // Suppose event1 is the first event observer received, then event2, event3.

[jeremy, 2014/02/16 14:09:19]

nit: the observer

[Pan, 2014/02/17 03:17:15]

Done.

+  // Then v2 is average power from t1 to t2, v3 is the average power from t2 to

[jeremy, 2014/02/16 14:09:19]

nit: the average

[Pan, 2014/02/17 03:17:15]

Done.

+  // t3. v1 should be ignored since event1 only means the start point of power
+  // profiling.
+  double value;
+};
+
+extern const char* kPowerTypeNames[];
+
+typedef std::vector<PowerEvent> PowerEventVector;
+
+// a class used to GET power usage.

[jeremy, 2014/02/16 14:09:19]

nit: s/a/A/
nit: lowercase get ?

[Pan, 2014/02/17 03:17:15]

Done.

+class PowerDataProvider {
+ public:
+  PowerDataProvider() {}
+  virtual ~PowerDataProvider() {}
+
+  // Return a vector of power events, one per type,
+  // due to the type it supports.

[jeremy, 2014/02/16 14:09:19]

nit: 'Returns' ,  s/due/for/

[Pan, 2014/02/17 03:17:15]

Done.

+  virtual PowerEventVector GetData() = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PowerDataProvider);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_POWER_PROFILER_POWER_DATA_PROVIDER_H_