Refactor AccelerometerReader to provide an Observer

ash/accelerometer/accelerometer_controller.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 "ash/accelerometer/accelerometer_controller.h"
-
-#include "ash/accelerometer/accelerometer_observer.h"
-
-namespace ash {
-
-AccelerometerController::AccelerometerController() {
-}
-
-AccelerometerController::~AccelerometerController() {
-}
-
-void AccelerometerController::Initialize(
-    scoped_refptr<base::TaskRunner> blocking_task_runner) {
-#if defined(OS_CHROMEOS)
-  reader_.reset(
-      new chromeos::AccelerometerReader(blocking_task_runner, this));
-#endif
-}
-
-void AccelerometerController::AddObserver(AccelerometerObserver* observer) {
-  observers_.AddObserver(observer);
-}
-
-void AccelerometerController::RemoveObserver(AccelerometerObserver* observer) {
-  observers_.RemoveObserver(observer);
-}
-
-#if defined(OS_CHROMEOS)
-void AccelerometerController::HandleAccelerometerUpdate(
-    const ui::AccelerometerUpdate& update) {
-  FOR_EACH_OBSERVER(AccelerometerObserver, observers_,
-      OnAccelerometerUpdated(update));
-}
-#endif
-
-}  // namespace ash