Migrates battery_status from content/renderer/ to WebKit/platform/

third_party/WebKit/Source/platform/battery/battery_status.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 BLINK_PLATFORM_BATTERY_BATTERY_STATUS_H_
+#define BLINK_PLATFORM_BATTERY_BATTERY_STATUS_H_
+
+#include "platform/PlatformExport.h"
+#include "wtf/Assertions.h"
+
+#include <cmath>
+#include <limits>
+
+namespace blink {
+
+// Simple struct to hold the battery status.  This class is copyable.
+class PLATFORM_EXPORT BatteryStatus final {
+ public:
+  BatteryStatus()
+      : charging_(true),
+        charging_time_(0),
+        discharging_time_(std::numeric_limits<double>::infinity()),
+        level_(1) {}
+  BatteryStatus(bool charging,
+                double charging_time,
+                double discharging_time,
+                double level)
+      : charging_(charging),
+        charging_time_(charging_time),
+        discharging_time_(discharging_time),
+        level_(EnsureTwoSignificantDigits(level)) {}
+  BatteryStatus(const BatteryStatus&) = default;
+  BatteryStatus& operator=(const BatteryStatus&) = default;
+
+  bool charging() const { return charging_; }
+  double charging_time() const { return charging_time_; }
+  double discharging_time() const { return discharging_time_; }
+  double level() const { return level_; }
+
+ private:
+  double EnsureTwoSignificantDigits(double level) {
+    // Convert battery level value which should be in [0, 1] to a value in
+    // [0, 1] with 2 digits of precision. This is to provide a consistent
+    // experience across platforms (e.g. on Mac and Android the battery changes
+    // are generally reported with 1% granularity). It also serves the purpose
+    // of reducing the possibility of fingerprinting and triggers less level
+    // change events on platforms where the granularity is high.
+    ASSERT(level >= 0 && level <= 1);
+    return std::round(level * 100) / 100.f;
+  }
+
+  bool charging_;
+  double charging_time_;
+  double discharging_time_;
+  double level_;
+};
+
+}  // namespace blink
+
+#endif  // BLINK_PLATFORM_BATTERY_BATTERY_STATUS_H_