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

ui/app_list/views/progress_bar_view.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 "ui/app_list/views/progress_bar_view.h"
 
 #include <algorithm>
 
 #include "grit/ui_resources.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 16 matching lines @@
 
 ProgressBarView::ProgressBarView()
     : background_painter_(views::Painter::CreateImagePainter(
           *ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
               IDR_APP_LIST_ITEM_PROGRESS_BACKGROUND),
           gfx::Insets(2, 2, 2, 2))),
       bar_painter_(new views::HorizontalPainter(kProgressBarImages)) {}
 
 ProgressBarView::~ProgressBarView() {}
 
-gfx::Size ProgressBarView::GetPreferredSize() {
+gfx::Size ProgressBarView::GetPreferredSize() const {
   return background_painter_->GetMinimumSize();
 }
 
 void ProgressBarView::OnPaint(gfx::Canvas* canvas) {
   gfx::Size paint_size = size();
 
   const gfx::Size min_size(background_painter_->GetMinimumSize());
   if (paint_size.width() < min_size.width() ||
       paint_size.height() < min_size.height()) {
     return;
   }
 
   background_painter_->Paint(canvas, paint_size);
 
   const int kBarEndWidth = 4;
   const int bar_width = paint_size.width() - kBarEndWidth;
   DCHECK_GE(bar_width, 0);
 
   // Map normalized value in [0,1] to the pixel width in
   // [kBarEndWidth, view_size.width()].
   paint_size.set_width(kBarEndWidth + bar_width * GetNormalizedValue());
   bar_painter_->Paint(canvas, paint_size);
 }
 
 }  // namespace app_list