views: provide feedback when editing fails

ui/views/controls/textfield/textfield.h

 // Copyright (c) 2012 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 UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_H_
 #define UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 374 matching lines @@
   void RevealPasswordChar(int index);
 
   void CreateTouchSelectionControllerAndNotifyIt();
 
   // Updates the selection clipboard to any non-empty text selection.
   void UpdateSelectionClipboard() const;
 
   // Pastes the selection clipboard for the specified mouse event.
   void PasteSelectionClipboard(const ui::MouseEvent& event);
 
+  // Called whenever an editing operation fails to provide visual or audio

[sky, 2016/09/16 17:34:36]

Why the visual/audio-feedback description? Isn't this more of 'called when a
keyevent is not handled for any reason, including the text-field is supplied a
keyevent and is read-only.

[Elly Fong-Jones, 2016/09/19 11:28:57]

Done.

+  // feedback to the user.
+  void OnEditFailed();
+
   // The text model.
   std::unique_ptr<TextfieldModel> model_;
 
   // This is the current listener for events from this Textfield.
   TextfieldController* controller_;
 
   // An edit command to execute on the next key event. When set to a valid
   // value, the key event is still passed to |controller_|, but otherwise
   // ignored in favor of the edit command. Set via
   // SetTextEditCommandForNextKeyEvent() during dispatch of that key event (see
@@ skipping 83 matching lines @@
 
   // Used to bind callback functions to this object.
   base::WeakPtrFactory<Textfield> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Textfield);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_H_