MacViews/a11y: Allow accessibility clients to update the selected text.

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/trace_event/trace_event.h"
@@ skipping 1806 matching lines @@
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
   if (text_input_type_ != ui::TEXT_INPUT_TYPE_PASSWORD) {
     ui::ScopedClipboardWriter(ui::CLIPBOARD_TYPE_SELECTION)
         .WriteText(GetSelectedText());
     if (controller_)
       controller_->OnAfterCutOrCopy(ui::CLIPBOARD_TYPE_SELECTION);
   }
 #endif
 }
 
-void Textfield::AccessibilitySetValue(const base::string16& new_value) {
-  if (!read_only()) {
+void Textfield::AccessibilitySetValue(const base::string16& new_value,
+                                      bool clear_first) {
+  if (read_only())
+    return;
+  if (!clear_first)
+    InsertOrReplaceText(new_value);
+  else
     SetText(new_value);
-    ClearSelection();
-  }
+  ClearSelection();
 }
 
 void Textfield::UpdateBackgroundColor() {
   const SkColor color = GetBackgroundColor();
   if (ui::MaterialDesignController::IsSecondaryUiMaterial()) {
     set_background(Background::CreateBackgroundPainter(
         true, Painter::CreateSolidRoundRectPainter(
                   color, FocusableBorder::kCornerRadiusDp)));
   } else {
     set_background(Background::CreateSolidBackground(color));
@@ skipping 199 matching lines @@
 }
 
 void Textfield::OnCursorBlinkTimerFired() {
   DCHECK(ShouldBlinkCursor());
   gfx::RenderText* render_text = GetRenderText();
   render_text->set_cursor_visible(!render_text->cursor_visible());
   RepaintCursor();
 }
 
 }  // namespace views