Battery Status API: add plumbing for multi-platform support.

content/browser/battery_status/battery_status_manager_default.cc

+// 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 "content/browser/battery_status/battery_status_manager.h"
+
+#include "base/logging.h"
+
+namespace content {
+
+BatteryStatusManager::BatteryStatusManager(
+    const BatteryStatusUpdateCallback& callback) : callback_(callback) {
+}
+
+BatteryStatusManager::~BatteryStatusManager() {
+}
+
+bool BatteryStatusManager::StartListeningBatteryChange() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
+void BatteryStatusManager::StopListeningBatteryChange() {
+  NOTIMPLEMENTED();
+}
+
+}  // namespace content