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

ash/frame/caption_buttons/frame_caption_button_container_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 "ash/frame/caption_buttons/frame_caption_button_container_view.h"
 
 #include <cmath>
 
 #include "ash/ash_switches.h"
 #include "ash/frame/caption_buttons/frame_caption_button.h"
@@ skipping 113 matching lines @@
   // TODO(flackr): Refactor the Maximize Mode notifications. Currently
   // UpdateSizeButtonVisibilty requires a force_hidden parameter. This is
   // because Shell::IsMaximizeWindowManagerEnabled is still false at the
   // time when ShellObserver::OnMaximizeModeStarted is called. This prevents
   // this method from performing that check, and instead relies on the calling
   // code to tell it to force being hidden.
   size_button_->SetVisible(
       !force_hidden && frame_->widget_delegate()->CanMaximize());
 }
 
-gfx::Size FrameCaptionButtonContainerView::GetPreferredSize() {
+gfx::Size FrameCaptionButtonContainerView::GetPreferredSize() const {
   int width = 0;
   for (int i = 0; i < child_count(); ++i) {
-    views::View* child = child_at(i);
+    const views::View* child = child_at(i);
     if (child->visible())
       width += child_at(i)->GetPreferredSize().width();
   }
   return gfx::Size(width, close_button_->GetPreferredSize().height());
 }
 
 void FrameCaptionButtonContainerView::Layout() {
   int x = 0;
   for (int i = 0; i < child_count(); ++i) {
     views::View* child = child_at(i);
@@ skipping 156 matching lines @@
     : icon_image_id(icon_id),
       inactive_icon_image_id(inactive_icon_id),
       hovered_background_image_id(hovered_background_id),
       pressed_background_image_id(pressed_background_id) {
 }
 
 FrameCaptionButtonContainerView::ButtonIconIds::~ButtonIconIds() {
 }
 
 }  // namespace ash