MacViews: Implement Full Keyboard Access.

ui/views/controls/tree/tree_view.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/tree/tree_view.h"
 
 #include <algorithm>
 
 #include "base/i18n/rtl.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 63 matching lines @@
     : model_(NULL),
       selected_node_(NULL),
       editing_(false),
       editor_(NULL),
       focus_manager_(NULL),
       auto_expand_children_(false),
       editable_(true),
       controller_(NULL),
       root_shown_(true),
       row_height_(font_list_.GetHeight() + kTextVerticalPadding * 2) {
+  // On Mac, only textfields and lists are focusable by default. Since TreeView
+  // represents a list, use ALWAYS focus behavior.

[tapted, 2016/04/20 06:05:58]

This could be

// Always focusable, even on Mac (consistent with NS<whatever it is>).

[karandeepb, 2016/05/03 02:54:13]

Done.

   SetFocusBehavior(FocusBehavior::ALWAYS);
   closed_icon_ = *ui::ResourceBundle::GetSharedInstance().GetImageNamed(
       (base::i18n::IsRTL() ? IDR_FOLDER_CLOSED_RTL
                            : IDR_FOLDER_CLOSED)).ToImageSkia();
   open_icon_ = *ui::ResourceBundle::GetSharedInstance().GetImageNamed(
       (base::i18n::IsRTL() ? IDR_FOLDER_OPEN_RTL
                            : IDR_FOLDER_OPEN)).ToImageSkia();
   text_offset_ = closed_icon_.width() + kImagePadding + kImagePadding +
       kArrowRegionSize;
 }
@@ skipping 949 matching lines @@
   if (!is_expanded_)
     return max_width;
   for (int i = 0; i < child_count(); ++i) {
     max_width = std::max(max_width,
                          GetChild(i)->GetMaxWidth(indent, depth + 1));
   }
   return max_width;
 }
 
 }  // namespace views