This change is intended to M-43. Currently screen rotation animations expose a...

This change is intended to M-43. Currently screen rotation animations expose a bug, causing the login screen to not be useable.

Disable rotation animations while a user is not logged in. This will be later reverted on M-44 where a fix to the underlying issue will be landed.

TEST=manual testing on device
BUG=chrome-os-partner:40118

Review URL: https://codereview.chromium.org/1139793003

Cr-Commit-Position: refs/heads/master@{#330100}

ash/rotator/screen_rotation_animator.cc

@@ -12,6 +12,7 @@
 #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"
@@ -280,10 +281,19 @@ 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();
+             ->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;
 }
 
 void ScreenRotationAnimator::Rotate(gfx::Display::Rotation new_rotation,