[MacViews] Implemented text context menu

ui/views/controls/textfield/views_text_context_menu_mac.cc

+// Copyright 2016 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/views_text_context_menu_mac.h"
+
+#include "ui/views/controls/textfield/textfield.h"
+
+namespace views {
+
+ViewsTextContextMenu* ViewsTextContextMenu::Create(Textfield* textfield) {

[tapted, 2016/07/22 03:06:42]

// static

[spqchan, 2016/12/12 19:32:28]

Done.

+  return new ViewsTextContextMenuMac(textfield);
+}
+
+ViewsTextContextMenuMac::ViewsTextContextMenuMac(Textfield* textfield)
+    : textfield_(textfield) {
+  menu_.reset(new TextContextMenu(this));
+}
+
+ViewsTextContextMenuMac::~ViewsTextContextMenuMac() {}
+
+void ViewsTextContextMenuMac::UpdateContextMenu(ui::SimpleMenuModel* menu) {
+  menu_->AppendToContextMenu(menu);
+}
+
+void ViewsTextContextMenuMac::StartSpeaking() {
+  base::string16 text = textfield_->GetSelectedText();

[tapted, 2016/07/22 03:06:42]

instead of GetSelectedText, this could use the TextInputClient API and 

GetSelectionRange(&foo)
GetTextFromRange(foo, &text);

this has a benefit of not trying to read out password fields, and it reduces the
coupling to `views`. I'm unsure if this is better though - it might be wrong to
couple it with IME. And it's not always "input" that we can read out.

The coupling to views could also be done by having ViewsTextContextMenuMac
declare its own, custom delegate interface, and have Textfield implement it, 
rather than just leaning on Textfield's full interface.

Right now, I'm leaning towards using TextInputClient. We should also support
speaking when there is no selected text. This is also straightforward-- if the
range reported by GetSelectionRange is empty, just get a range from
GetTextRange() to read out the whole textfield

[spqchan, 2016/12/12 19:32:28]

Sounds good, I switched to TextInputClient and moved the files

+  if (text.empty())
+    text = textfield_->text();
+
+  menu_->SpeakText(text);
+}
+
+}