views: Make view::Views::GetPreferredSize() const.

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 332 matching lines @@
   int width = preferred_size_.width();
   int height = preferred_size_.height();
   if (parent()) {
     width = std::max(parent()->width(), width);
     height = std::max(parent()->height(), height);
   }
   SetBounds(x(), y(), width, height);
   LayoutEditor();
 }
 
-gfx::Size TreeView::GetPreferredSize() {
+gfx::Size TreeView::GetPreferredSize() const {
   return preferred_size_;
 }
 
 bool TreeView::AcceleratorPressed(const ui::Accelerator& accelerator) {
   if (accelerator.key_code() == ui::VKEY_RETURN) {
     CommitEdit();
   } else {
     DCHECK_EQ(ui::VKEY_ESCAPE, accelerator.key_code());
     CancelEdit();
     RequestFocus();
@@ skipping 671 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