MacViews/a11y: Allow accessibility clients to set new selections in Textfields.

ui/views/controls/textfield/textfield.cc

 // 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.
 
 #include "ui/views/controls/textfield/textfield.h"
 
 #include <string>
 #include <utility>
 
 #include "base/memory/ptr_util.h"
@@ skipping 1397 matching lines @@
 }
 
 bool Textfield::GetSelectionRange(gfx::Range* range) const {
   if (!ImeEditingAllowed())
     return false;
   *range = GetRenderText()->selection();
   return true;
 }
 
 bool Textfield::SetSelectionRange(const gfx::Range& range) {
-  if (!ImeEditingAllowed() || !range.IsValid())
+  if (!enabled() || !range.IsValid())

[tapted, 2017/02/14 05:45:32]

as discussed - I'm not sure about changing this without changing a few other
sites in textfield.cc. And after checking password fields in Cocoa, the right
thing to do might be to make the selected range attribute unmodifiable via a11y
to be consistent (and having the test verify this). But that's fine as a
follow-up with a note in the test that the behaviour is inconsistent with Cocoa
(i.e. NSAccessibilitySelectedTextRangeAttribute shouldn't be settable after
doing SetReadOnly(true).

[Patti Lor, 2017/02/15 06:34:47]

Yep, so as discovered & discussed offline, selection-only NSTextfields allow
setting SelectedTextRange via a11y, but not NSSecureTextfields. I've reverted
this file, and added a note in the test to say that we deviate from Cocoa
behaviour here & filed https://crbug.com/692362.

     return false;
   OnBeforeUserAction();
   SelectRange(range);
   OnAfterUserAction();
   return true;
 }
 
 bool Textfield::DeleteRange(const gfx::Range& range) {
   if (!ImeEditingAllowed() || range.is_empty())
     return false;
@@ skipping 667 matching lines @@
 }
 
 void Textfield::OnCursorBlinkTimerFired() {
   DCHECK(ShouldBlinkCursor());
   gfx::RenderText* render_text = GetRenderText();
   render_text->set_cursor_visible(!render_text->cursor_visible());
   RepaintCursor();
 }
 
 }  // namespace views