ui: Cleanup class/struct forward declarations

ui/views/round_rect_painter.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_VIEWS_ROUNDED_RECT_PAINTER_H_
 #define UI_VIEWS_ROUNDED_RECT_PAINTER_H_
 
 #include "base/macros.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/views/painter.h"
 #include "ui/views/views_export.h"
 
 namespace gfx {
 class Canvas;
-class Path;
 class Size;
 }
 
 namespace views {
 
 // Painter to draw a border with rounded corners.
 class VIEWS_EXPORT RoundRectPainter : public Painter {
  public:
   enum { kBorderWidth = 1 };
 
   RoundRectPainter(SkColor border_color, int corner_radius);
   ~RoundRectPainter() override;
 
   // Painter:
   gfx::Size GetMinimumSize() const override;
   void Paint(gfx::Canvas* canvas, const gfx::Size& size) override;
 
  private:
   const SkColor border_color_;
   const int corner_radius_;
 
   DISALLOW_COPY_AND_ASSIGN(RoundRectPainter);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_ROUNDED_RECT_PAINTER_H_