no virtual destructor for point/size/rect

ui/gfx/size_base.h

 // 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.
 
 #ifndef UI_GFX_SIZE_BASE_H_
 #define UI_GFX_SIZE_BASE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 41 matching lines @@
     return !(*this == s);
   }
 
   bool IsEmpty() const {
     // Size doesn't allow negative dimensions, so testing for 0 is enough.
     return (width_ == 0) || (height_ == 0);
   }
 
  protected:
   SizeBase(Type width, Type height);
-  virtual ~SizeBase();
+  // Destructor is intentionally made non virtual and protected.
+  // Do not make this public.
+  ~SizeBase();
 
  private:
   Type width_;
   Type height_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_SIZE_BASE_H_