Change AccelerometerReader to a Singleton

ash/content/display/screen_orientation_controller_chromeos.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/content/display/screen_orientation_controller_chromeos.h"
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
@@ skipping 56 matching lines @@
       rotation_locked_(false),
       user_rotation_(gfx::Display::ROTATE_0),
       current_rotation_(gfx::Display::ROTATE_0) {
   content::ScreenOrientationProvider::SetDelegate(this);
   Shell::GetInstance()->AddShellObserver(this);
 }
 
 ScreenOrientationController::~ScreenOrientationController() {
   content::ScreenOrientationProvider::SetDelegate(NULL);
   Shell::GetInstance()->RemoveShellObserver(this);
-  Shell::GetInstance()->accelerometer_reader()->RemoveObserver(this);
+  chromeos::AccelerometerReader::GetInstance()->RemoveObserver(this);
   Shell::GetInstance()->display_controller()->RemoveObserver(this);
 }
 
 void ScreenOrientationController::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
 
 void ScreenOrientationController::RemoveObserver(Observer* observer) {
   observers_.RemoveObserver(observer);
 }
@@ skipping 125 matching lines @@
 }
 
 void ScreenOrientationController::OnMaximizeModeStarted() {
   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
   if (!display_manager->HasInternalDisplay())
     return;
   current_rotation_ = user_rotation_ =
       display_manager->GetDisplayInfo(gfx::Display::InternalDisplayId())
           .rotation();
   LoadDisplayRotationProperties();
-  Shell::GetInstance()->accelerometer_reader()->AddObserver(this);
+  chromeos::AccelerometerReader::GetInstance()->AddObserver(this);
   Shell::GetInstance()->display_controller()->AddObserver(this);
 }
 
 void ScreenOrientationController::OnMaximizeModeEnded() {
   if (!Shell::GetInstance()->display_manager()->HasInternalDisplay())
     return;
-  Shell::GetInstance()->accelerometer_reader()->RemoveObserver(this);
+  chromeos::AccelerometerReader::GetInstance()->RemoveObserver(this);
   Shell::GetInstance()->display_controller()->RemoveObserver(this);
   if (current_rotation_ != user_rotation_)
     SetDisplayRotation(user_rotation_);
 }
 
 void ScreenOrientationController::LockRotation(
     gfx::Display::Rotation rotation) {
   SetRotationLocked(true);
   SetDisplayRotation(rotation);
 }
@@ skipping 92 matching lines @@
 
 void ScreenOrientationController::LoadDisplayRotationProperties() {
   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
   if (!display_manager->registered_internal_display_rotation_lock())
     return;
   SetDisplayRotation(display_manager->registered_internal_display_rotation());
   SetRotationLocked(true);
 }
 
 }  // namespace ash