Change AccelerometerReader to a Singleton

ash/wm/maximize_mode/maximize_mode_controller_unittest.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 <math.h>
 
 #include "ash/wm/maximize_mode/maximize_mode_controller.h"
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_manager.h"
@@ skipping 39 matching lines @@
 extern const float kAccelerometerFullyOpenTestData[];
 extern const size_t kAccelerometerFullyOpenTestDataLength;
 
 class MaximizeModeControllerTest : public test::AshTestBase {
  public:
   MaximizeModeControllerTest() {}
   ~MaximizeModeControllerTest() override {}
 
   void SetUp() override {
     test::AshTestBase::SetUp();
-    Shell::GetInstance()->accelerometer_reader()->RemoveObserver(
+    chromeos::AccelerometerReader::GetInstance()->RemoveObserver(
         maximize_mode_controller());
 
     // Set the first display to be the internal display for the accelerometer
     // screen rotation tests.
     test::DisplayManagerTestApi(Shell::GetInstance()->display_manager()).
         SetFirstDisplayAsInternalDisplay();
   }
 
   void TearDown() override {
-    Shell::GetInstance()->accelerometer_reader()->AddObserver(
+    chromeos::AccelerometerReader::GetInstance()->AddObserver(
         maximize_mode_controller());
     test::AshTestBase::TearDown();
   }
 
   MaximizeModeController* maximize_mode_controller() {
     return Shell::GetInstance()->maximize_mode_controller();
   }
 
   void TriggerLidUpdate(const gfx::Vector3dF& lid) {
     ui::AccelerometerUpdate update;
@@ skipping 564 matching lines @@
   // Would normally trigger an exit from maximize mode.
   OpenLidToAngle(90.0f);
   EXPECT_TRUE(IsMaximizeModeStarted());
 
   TriggerBaseAndLidUpdate(gfx::Vector3dF(-kMeanGravity, 0.0f, 0.0f),
                           gfx::Vector3dF(-kMeanGravity, 0.0f, 0.0f));
   EXPECT_EQ(gfx::Display::ROTATE_90, GetInternalDisplayRotation());
 }
 
 }  // namespace ash