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

ash/system/tray/tray_bar_button_with_title.cc

 // Copyright 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 "ash/system/tray/tray_bar_button_with_title.h"
 
 #include "ash/system/tray/tray_constants.h"
 #include "base/memory/scoped_ptr.h"
 #include "grit/ui_resources.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 66 matching lines @@
   image_height_ = ui::ResourceBundle::GetSharedInstance().GetImageNamed(
       kBarImagesActive[0]).ToImageSkia()->height();
 }
 
 TrayBarButtonWithTitle::~TrayBarButtonWithTitle() {}
 
 void TrayBarButtonWithTitle::UpdateButton(bool control_on) {
   image_->Update(control_on);
 }
 
-gfx::Size TrayBarButtonWithTitle::GetPreferredSize() {
+gfx::Size TrayBarButtonWithTitle::GetPreferredSize() const {
   return gfx::Size(width_, kTrayPopupItemHeight);
 }
 
 void TrayBarButtonWithTitle::Layout() {
   gfx::Rect rect(GetContentsBounds());
   int bar_image_y = rect.height() / 2 - image_height_ / 2;
   gfx::Rect bar_image_rect(rect.x(),
                            bar_image_y,
                            rect.width(),
                            image_height_);
   image_->SetBoundsRect(bar_image_rect);
   if (title_) {
     // The image_ has some empty space below the bar image, move the title
     // a little bit up to look closer to the bar.
     gfx::Size title_size = title_->GetPreferredSize();
     title_->SetBounds(rect.x(),
                       bar_image_y + image_height_ - 3,
                       rect.width(),
                       title_size.height());
   }
 }
 
 }  // namespace ash