Properly set ShelfAlignment during login

ash/test/test_session_state_delegate.h

Index: ash/test/test_session_state_delegate.h
diff --git a/ash/test/test_session_state_delegate.h b/ash/test/test_session_state_delegate.h
index a77b3cdbeaf8cce57c8ada74ed257a656bcf233a..b35f8642d1a60dbaf11901b8345216901c95fb12 100644
--- a/ash/test/test_session_state_delegate.h
+++ b/ash/test/test_session_state_delegate.h
@@ -23,6 +23,9 @@ class TestSessionStateDelegate : public SessionStateDelegate {
   ~TestSessionStateDelegate() override;
 
   void set_logged_in_users(int users) { logged_in_users_ = users; }
+  void set_session_state(SessionState session_state) {
+    session_state_ = session_state;
+  }
   void AddUser(const std::string user_id);
   const user_manager::UserInfo* GetActiveUserInfo() const;
 
@@ -111,6 +114,10 @@ class TestSessionStateDelegate : public SessionStateDelegate {
 
   std::vector<MockUserInfo*> user_list_;
 
+  // The current state of the login screen. |session_state_| becomes active
+  // before the profile and browser UI are available.
+  SessionState session_state_;
+
   DISALLOW_COPY_AND_ASSIGN(TestSessionStateDelegate);
 };