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

ui/views/controls/button/label_button.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/button/label_button.h"
 
 #include "base/logging.h"
 #include "grit/ui_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/animation/throb_animation.h"
@@ skipping 155 matching lines @@
   if (style == STYLE_BUTTON)
     set_min_size(gfx::Size(70, 33));
 
   OnNativeThemeChanged(GetNativeTheme());
 }
 
 void LabelButton::SetFocusPainter(scoped_ptr<Painter> focus_painter) {
   focus_painter_ = focus_painter.Pass();
 }
 
-gfx::Size LabelButton::GetPreferredSize() {
+gfx::Size LabelButton::GetPreferredSize() const {
   // Use a temporary label copy for sizing to avoid calculation side-effects.
   Label label(GetText(), cached_normal_font_list_);
   label.SetMultiLine(GetTextMultiLine());
 
   if (style() == STYLE_BUTTON) {
     // Some text appears wider when rendered normally than when rendered bold.
     // Accommodate the widest, as buttons may show bold and shouldn't resize.
     const int current_width = label.GetPreferredSize().width();
     label.SetFontList(cached_bold_font_list_);
     if (label.GetPreferredSize().width() < current_width)
@@ skipping 241 matching lines @@
   return ui::NativeTheme::kNormal;
 }
 
 ui::NativeTheme::State LabelButton::GetForegroundThemeState(
     ui::NativeTheme::ExtraParams* params) const {
   GetExtraParams(params);
   return ui::NativeTheme::kHovered;
 }
 
 }  // namespace views