Show a notification when a braille display is connected.

ash/accessibility_delegate.h

Index: ash/accessibility_delegate.h
diff --git a/ash/accessibility_delegate.h b/ash/accessibility_delegate.h
index 037a40f83024aa468047e776eb4aa66130e206b9..7a1b4007e778940e59dea73283e0b0b3c3051a60 100644
--- a/ash/accessibility_delegate.h
+++ b/ash/accessibility_delegate.h
@@ -21,7 +21,7 @@ enum AccessibilityAlert {
   A11Y_ALERT_WINDOW_NEEDED
 };
 
-// A deletate class to control accessibility features.
+// A delegate class to control and query accessibility features.
 class ASH_EXPORT AccessibilityDelegate {
  public:
   virtual ~AccessibilityDelegate() {}
@@ -45,7 +45,7 @@ class ASH_EXPORT AccessibilityDelegate {
   // Invoked to change the type of the screen magnifier.
   virtual void SetMagnifierType(MagnifierType type) = 0;
 
-  // Returns true if the screen magnifier is enabled or not.
+  // Returns true if the screen magnifier is enabled.
   virtual bool IsMagnifierEnabled() const = 0;
 
   // Returns the current screen magnifier mode.
@@ -54,7 +54,7 @@ class ASH_EXPORT AccessibilityDelegate {
   // Invoked to enable Large Cursor.
   virtual void SetLargeCursorEnabled(bool enabled) = 0;
 
-  // Returns ture if Large Cursor is enabled or not.
+  // Returns ture if Large Cursor is enabled.
   virtual bool IsLargeCursorEnabled() const = 0;
 
   // Invoked to enable autoclick.
@@ -72,6 +72,9 @@ class ASH_EXPORT AccessibilityDelegate {
   // Returns true when the accessibility menu should be shown.
   virtual bool ShouldShowAccessibilityMenu() const = 0;
 
+  // Returns true if a braille display is connected to the system.
+  virtual bool IsBrailleDisplayConnected() const = 0;
+
   // Cancel all current and queued speech immediately.
   virtual void SilenceSpokenFeedback() const = 0;