Revert 167062 - ui: Remove gfx::Size::ClampToNonNegative, prevent negative sizes always.

ui/gfx/rect_f.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_RECT_F_H_
 #define UI_GFX_RECT_F_H_
 
 #include <string>
 
 #include "ui/gfx/point_f.h"
@@ skipping 19 matching lines @@
 
   /// Scales the rectangle by |scale|.
   void Scale(float scale) {
     Scale(scale, scale);
   }
 
   void Scale(float x_scale, float y_scale) {
     set_origin(ScalePoint(origin(), x_scale, y_scale));
 
     SizeF new_size = size().Scale(x_scale, y_scale);
+    new_size.ClampToNonNegative();
     set_size(new_size);
   }
 
   // This method reports if the RectF can be safely converted to an integer
   // Rect. When it is false, some dimension of the RectF is outside the bounds
   // of what an integer can represent, and converting it to a Rect will require
   // clamping.
   bool IsExpressibleAsRect() const;
 
   std::string ToString() const;
@@ skipping 31 matching lines @@
 // contained within the rect, because they will appear on one of these edges.
 UI_EXPORT RectF BoundingRect(const PointF& p1, const PointF& p2);
 
 #if !defined(COMPILER_MSVC)
 extern template class RectBase<RectF, PointF, SizeF, InsetsF, Vector2dF, float>;
 #endif
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RECT_F_H_