Accessibility manager shouldn't try to access ash Shelf from login screen.

chrome/browser/chromeos/accessibility/accessibility_manager.h

Index: chrome/browser/chromeos/accessibility/accessibility_manager.h
diff --git a/chrome/browser/chromeos/accessibility/accessibility_manager.h b/chrome/browser/chromeos/accessibility/accessibility_manager.h
index a6cb843f7db9d001bd47846c8ebfaed8d3a17b21..8f3f518d2d3a86cb268425636dd15cd4d1475a02 100644
--- a/chrome/browser/chromeos/accessibility/accessibility_manager.h
+++ b/chrome/browser/chromeos/accessibility/accessibility_manager.h
@@ -242,6 +242,10 @@ class AccessibilityManager
   void OnChromeVoxPanelClosing();
   void OnChromeVoxPanelDestroying();
 
+  // Called when switching profiles so we can make sure the panel height
+  // is set.
+  void UpdateChromeVoxPanelHeight();
+
   // Profile having the a11y context.
   Profile* profile() { return profile_; }