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

ui/app_list/views/folder_header_view.cc

 // Copyright (c) 2013 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/app_list/views/folder_header_view.h"
 
 #include <algorithm>
 
 #include "base/strings/utf_string_conversions.h"
 #include "grit/ui_resources.h"
@@ skipping 130 matching lines @@
 }
 
 void FolderHeaderView::SetFolderNameForTest(const base::string16& name) {
   folder_name_view_->SetText(name);
 }
 
 bool FolderHeaderView::IsFolderNameEnabledForTest() const {
   return folder_name_view_->enabled();
 }
 
-gfx::Size FolderHeaderView::GetPreferredSize() {
+gfx::Size FolderHeaderView::GetPreferredSize() const {
   return gfx::Size(kPreferredWidth, kPreferredHeight);
 }
 
 void FolderHeaderView::Layout() {
   gfx::Rect rect(GetContentsBounds());
   if (rect.IsEmpty())
     return;
 
   gfx::Rect back_bounds(rect);
   back_bounds.set_width(kIconDimension + 2 * kPadding);
@@ skipping 70 matching lines @@
 void FolderHeaderView::ItemHighlightedChanged() {
 }
 
 void FolderHeaderView::ItemIsInstallingChanged() {
 }
 
 void FolderHeaderView::ItemPercentDownloadedChanged() {
 }
 
 }  // namespace app_list