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

ui/views/widget/widget_unittest.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 <algorithm>
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 107 matching lines @@
 };
 
 // A view that implements GetMinimumSize.
 class MinimumSizeFrameView : public NativeFrameView {
  public:
   explicit MinimumSizeFrameView(Widget* frame): NativeFrameView(frame) {}
   virtual ~MinimumSizeFrameView() {}
 
  private:
   // Overridden from View:
-  virtual gfx::Size GetMinimumSize() OVERRIDE {
+  virtual gfx::Size GetMinimumSize() const OVERRIDE {
     return gfx::Size(300, 400);
   }
 
   DISALLOW_COPY_AND_ASSIGN(MinimumSizeFrameView);
 };
 
 // An event handler that simply keeps a count of the different types of events
 // it receives.
 class EventCountHandler : public ui::EventHandler {
  public:
@@ skipping 2324 matching lines @@
   child_widget.Init(child_params);
   child_widget.AddObserver(&observer);
   child_widget.Show();
 
   parent_widget.CloseNow();
 }
 #endif
 
 }  // namespace test
 }  // namespace views