Revert Disable Rotation on Login Pages

ash/rotator/screen_rotation_animator.cc

 // Copyright 2015 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/rotator/screen_rotation_animator.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_controller.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/rotator/screen_rotation_animation.h"
-#include "ash/session/session_state_delegate.h"
 #include "ash/shell.h"
 #include "base/command_line.h"
 #include "base/time/time.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/compositor/layer_animation_sequence.h"
 #include "ui/compositor/layer_animator.h"
 #include "ui/compositor/layer_owner.h"
 #include "ui/compositor/layer_tree_owner.h"
@@ skipping 248 matching lines @@
 }  // namespace
 
 ScreenRotationAnimator::ScreenRotationAnimator(int64 display_id)
     : display_id_(display_id) {
 }
 
 ScreenRotationAnimator::~ScreenRotationAnimator() {
 }
 
 bool ScreenRotationAnimator::CanAnimate() const {
-  // Animations are currently broken on the login screen.
-  // (chrome-os-partners:40118). Disabling the animations on this screen for
-  // M-43
   return Shell::GetInstance()
-             ->display_manager()
-             ->GetDisplayForId(display_id_)
-             .is_valid() &&
-         Shell::GetInstance()
-             ->session_state_delegate()
-             ->IsActiveUserSessionStarted() &&
-         !Shell::GetInstance()->session_state_delegate()->IsScreenLocked() &&
-         Shell::GetInstance()->session_state_delegate()->GetSessionState() ==
-             SessionStateDelegate::SESSION_STATE_ACTIVE;
+      ->display_manager()
+      ->GetDisplayForId(display_id_)
+      .is_valid();
 }
 
 void ScreenRotationAnimator::Rotate(gfx::Display::Rotation new_rotation,
                                     gfx::Display::RotationSource source) {
   const gfx::Display::Rotation current_rotation =
       GetCurrentRotation(display_id_);
 
   if (current_rotation == new_rotation)
     return;
 
@@ skipping 22 matching lines @@
     RotateScreen(display_id_, new_rotation, source,
                  base::TimeDelta::FromMilliseconds(kRotationDurationInMs),
                  rotation_degrees, 0 /* rotation_degree_offset */,
                  gfx::Tween::FAST_OUT_LINEAR_IN, true /* should_scale */);
   } else {
     NOTREACHED();
   }
 }
 
 }  // namespace ash