Show ChromeVox caption panel when spoken feedback is enabled.

ash/accessibility_delegate.h

 // Copyright 2013 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.
 
 #ifndef ASH_ACCESSIBILITY_DELEGATE_H_
 #define ASH_ACCESSIBILITY_DELEGATE_H_
 
 #include "ash/ash_export.h"
 #include "base/time/time.h"
 #include "ui/chromeos/accessibility_types.h"
+#include "ui/gfx/geometry/insets.h"
+
+namespace aura {
+class Window;
+}
 
 namespace ash {
 
 // A delegate class to control and query accessibility features.
 class ASH_EXPORT AccessibilityDelegate {
  public:
   virtual ~AccessibilityDelegate() {}
 
   // Invoked to toggle spoken feedback for accessibility
   virtual void ToggleSpokenFeedback(
@@ skipping 60 matching lines @@
   // Gets the last accessibility alert that was triggered.
   virtual ui::AccessibilityAlert GetLastAccessibilityAlert() = 0;
 
   // Plays an earcon. Earcons are brief and distinctive sounds that indicate
   // when their mapped event has occurred. The sound key enums can be found in
   // chromeos/audio/chromeos_sounds.h.
   virtual void PlayEarcon(int sound_key) = 0;
 
   // Initiates play of shutdown sound and returns it's duration.
   virtual base::TimeDelta PlayShutdownSound() const = 0;
+
+  // Get work area insets due to accessibility overlays on one of the
+  // screen edges, for the given root window.
+  virtual gfx::Insets GetWorkAreaInsets(aura::Window* root_window) const = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_ACCESSIBILITY_DELEGATE_H_