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

ui/views/controls/progress_bar.h

 // Copyright (c) 2011 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.
 
 #ifndef UI_VIEWS_CONTROLS_PROGRESS_BAR_H_
 #define UI_VIEWS_CONTROLS_PROGRESS_BAR_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/views/view.h"
@@ skipping 28 matching lines @@
 
   // Overridden from View:
   virtual bool GetTooltipText(const gfx::Point& p,
                               base::string16* tooltip) const OVERRIDE;
   virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
 
  private:
   static const char kViewClassName[];
 
   // Overridden from View:
-  virtual gfx::Size GetPreferredSize() OVERRIDE;
+  virtual gfx::Size GetPreferredSize() const OVERRIDE;
   virtual const char* GetClassName() const OVERRIDE;
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
 
   // Inclusive range used when displaying values.
   double min_display_value_;
   double max_display_value_;
 
   // Current value.  May be outside of [min_display_value_, max_display_value_].
   double current_value_;
 
   // Tooltip text.
   base::string16 tooltip_text_;
 
   DISALLOW_COPY_AND_ASSIGN(ProgressBar);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_PROGRESS_BAR_H_