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

ui/views/controls/table/table_header.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/table/table_header.h"
 
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/text_utils.h"
@@ skipping 141 matching lines @@
         indicator_path.lineTo(
             SkIntToScalar(indicator_x + kSortIndicatorSize / 2 * scale),
             SkIntToScalar(indicator_y + kSortIndicatorSize));
       }
       indicator_path.close();
       canvas->DrawPath(indicator_path, paint);
     }
   }
 }
 
-gfx::Size TableHeader::GetPreferredSize() {
+gfx::Size TableHeader::GetPreferredSize() const {
   return gfx::Size(1, kVerticalPadding * 2 + font_list_.GetHeight());
 }
 
 gfx::NativeCursor TableHeader::GetCursor(const ui::MouseEvent& event) {
   return GetResizeColumn(GetMirroredXInView(event.x())) != -1 ?
       GetNativeColumnResizeCursor() : View::GetCursor(event);
 }
 
 bool TableHeader::OnMousePressed(const ui::MouseEvent& event) {
   if (event.IsOnlyLeftMouseButton()) {
@@ skipping 96 matching lines @@
   if (index > 0 && x >= column.x - kResizePadding &&
       x <= column.x + kResizePadding) {
     return index - 1;
   }
   const int max_x = column.x + column.width;
   return (x >= max_x - kResizePadding && x <= max_x + kResizePadding) ?
       index : -1;
 }
 
 }  // namespace views