Add support to Battery Status API in blink.

Source/modules/battery/NavigatorBattery.cpp

+// 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.
+
+#include "config.h"
+#include "modules/battery/NavigatorBattery.h"
+
+#include "core/frame/LocalFrame.h"
+#include "modules/battery/BatteryManager.h"
+
+namespace WebCore {
+
+NavigatorBattery::NavigatorBattery()
+{
+}
+
+NavigatorBattery::~NavigatorBattery()
+{
+}
+
+BatteryManager* NavigatorBattery::battery(Navigator& navigator)
+{
+    return NavigatorBattery::from(navigator).batteryManager(navigator);
+}
+
+BatteryManager* NavigatorBattery::batteryManager(Navigator& navigator)
+{
+    if (!m_batteryManager && navigator.frame())
+        m_batteryManager = BatteryManager::create(navigator.frame()->document());
+    return m_batteryManager.get();
+}
+
+const char* NavigatorBattery::supplementName()
+{
+    return "NavigatorBattery";
+}
+
+NavigatorBattery& NavigatorBattery::from(Navigator& navigator)
+{
+    NavigatorBattery* supplement = static_cast<NavigatorBattery*>(Supplement<Navigator>::from(navigator, supplementName()));
+    if (!supplement) {
+        supplement = new NavigatorBattery();
+        provideTo(navigator, supplementName(), adoptPtr(supplement));
+    }
+    return *supplement;
+}
+
+} // namespace WebCore