MacViews: Implement Full Keyboard Access.

ui/views/controls/combobox/combobox.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/combobox/combobox.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 336 matching lines @@
     : model_(model),
       style_(STYLE_NORMAL),
       listener_(NULL),
       selected_index_(model_->GetDefaultIndex()),
       invalid_(false),
       menu_model_adapter_(new ComboboxMenuModelAdapter(this, model)),
       text_button_(new TransparentButton(this)),
       arrow_button_(new TransparentButton(this)),
       weak_ptr_factory_(this) {
   ModelChanged();
+#if defined(OS_MACOSX)
+  SetFocusBehavior(FocusBehavior::ACCESSIBLE_ONLY);
+#else
   SetFocusBehavior(FocusBehavior::ALWAYS);
+#endif
+
   UpdateBorder();
   // set_background() takes ownership but takes a raw pointer.
   std::unique_ptr<Background> b = PlatformStyle::CreateComboboxBackground();
   set_background(b.release());
 
   // Initialize the button images.
   Button::ButtonState button_states[] = {
     Button::STATE_DISABLED,
     Button::STATE_NORMAL,
     Button::STATE_HOVERED,
@@ skipping 547 matching lines @@
   return gfx::Size(width, font_list.GetHeight());
 }
 
 PrefixSelector* Combobox::GetPrefixSelector() {
   if (!selector_)
     selector_.reset(new PrefixSelector(this));
   return selector_.get();
 }
 
 }  // namespace views