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

ash/wm/panels/panel_frame_view.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 "ash/wm/panels/panel_frame_view.h"
 
 #include "ash/frame/caption_buttons/frame_caption_button_container_view.h"
 #include "ash/frame/default_header_painter.h"
 #include "ash/frame/frame_border_hit_test_controller.h"
 #include "grit/ash_resources.h"
@@ skipping 41 matching lines @@
 
   header_painter_->Init(frame_, this, window_icon_, caption_button_container_);
 }
 
 int PanelFrameView::NonClientTopBorderHeight() const {
   if (!header_painter_)
     return 0;
   return header_painter_->GetHeaderHeightForPainting();
 }
 
-gfx::Size PanelFrameView::GetMinimumSize() {
+gfx::Size PanelFrameView::GetMinimumSize() const {
   if (!header_painter_)
     return gfx::Size();
   gfx::Size min_client_view_size(frame_->client_view()->GetMinimumSize());
   return gfx::Size(
       std::max(header_painter_->GetMinimumHeaderWidth(),
                min_client_view_size.width()),
       NonClientTopBorderHeight() + min_client_view_size.height());
 }
 
 void PanelFrameView::Layout() {
@@ skipping 50 matching lines @@
 }
 
 gfx::Rect PanelFrameView::GetWindowBoundsForClientBounds(
     const gfx::Rect& client_bounds) const {
   gfx::Rect window_bounds = client_bounds;
   window_bounds.Inset(0, -NonClientTopBorderHeight(), 0, 0);
   return window_bounds;
 }
 
 }  // namespace ash