views: don't use open-folder icons in TreeView on Mac

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/memory/ptr_util.h"
@@ skipping 762 matching lines @@
   }
 
   if (model_->GetChildCount(node->model_node()))
     PaintExpandControl(canvas, bounds, node->is_expanded());
 
   // Paint the icon.
   gfx::ImageSkia icon;
   int icon_index = model_->GetIconIndex(node->model_node());
   if (icon_index != -1)
     icon = icons_[icon_index];
-  else if (node == selected_node_)
+  else if (node == selected_node_ && PlatformStyle::kTreeViewUsesOpenIcon)
     icon = open_icon_;
   else
     icon = closed_icon_;
   int icon_x = kArrowRegionSize + kImagePadding +
                (open_icon_.width() - icon.width()) / 2;
   if (base::i18n::IsRTL())
     icon_x = bounds.right() - icon_x - open_icon_.width();
   else
     icon_x += bounds.x();
   canvas->DrawImageInt(
@@ skipping 303 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