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

third_party/WebKit/public/platform/WebBatteryStatus.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 WebBatteryStatus_h
-#define WebBatteryStatus_h
-
-#include <limits>
-
-namespace blink {
-
-class WebBatteryStatus {
-public:
-    WebBatteryStatus()
-        : charging(true)
-        , chargingTime(0.0)
-        , dischargingTime(std::numeric_limits<double>::infinity())
-        , level(1.0)
-    {
-    }
-
-    bool charging;
-    double chargingTime;
-    double dischargingTime;
-    double level;
-};
-
-} // namespace blink
-
-#endif // WebBatteryStatus_h