no virtual destructor for point/size/rect

ui/gfx/point_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_POINT_BASE_H_
 #define UI_GFX_POINT_BASE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 62 matching lines @@
   // the x-value closer to the origin is considered less than the
   // other.
   // This comparison is required to use Point in sets, or sorted
   // vectors.
   bool operator<(const Class& rhs) const {
     return (y_ == rhs.y_) ? (x_ < rhs.x_) : (y_ < rhs.y_);
   }
 
  protected:
   PointBase(Type x, Type y) : x_(x), y_(y) {}
-  virtual ~PointBase() {}
+  // Destructor is intentionally made non virtual and protected.
+  // Do not make this public.
+  ~PointBase() {}
 
  private:
   Type x_;
   Type y_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_POINT_BASE_H_