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

ui/app_list/views/page_switcher.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/app_list/views/page_switcher.h"
 
 #include <algorithm>
 
 #include "third_party/skia/include/core/SkPath.h"
 #include "ui/app_list/app_list_constants.h"
@@ skipping 31 matching lines @@
     if (selected_range_ == selected_range)
       return;
 
     selected_range_ = selected_range;
     SchedulePaint();
   }
 
   void set_button_width(int button_width) { button_width_ = button_width; }
 
   // Overridden from views::View:
-  virtual gfx::Size GetPreferredSize() OVERRIDE {
+  virtual gfx::Size GetPreferredSize() const OVERRIDE {
     return gfx::Size(button_width_, kButtonHeight);
   }
 
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
     if (state() == STATE_HOVERED)
       PaintButton(canvas, kPagerHoverColor);
     else
       PaintButton(canvas, kPagerNormalColor);
   }
 
@@ skipping 95 matching lines @@
     return;
   }
 
   for (int i = 0; i < button_count; ++i) {
     PageSwitcherButton* button =
         static_cast<PageSwitcherButton*>(buttons_->child_at(i));
     button->SetState(views::CustomButton::STATE_NORMAL);
   }
 }
 
-gfx::Size PageSwitcher::GetPreferredSize() {
+gfx::Size PageSwitcher::GetPreferredSize() const {
   // Always return a size with correct height so that container resize is not
   // needed when more pages are added.
   return gfx::Size(buttons_->GetPreferredSize().width(),
                    kPreferredHeight);
 }
 
 void PageSwitcher::Layout() {
   gfx::Rect rect(GetContentsBounds());
 
   CalculateButtonWidthAndSpacing(rect.width());
@@ skipping 79 matching lines @@
     remaining = -remaining;
     progress = -progress;
   }
 
   GetButtonByIndex(buttons_, current_page)->SetSelectedRange(remaining);
   if (model_->is_valid_page(target_page))
     GetButtonByIndex(buttons_, target_page)->SetSelectedRange(progress);
 }
 
 }  // namespace app_list