Add gfx::ToRoundedInt safe conversion method from float to int.

ui/gfx/size_conversions.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 "ui/gfx/size_conversions.h"
 
-#include "ui/gfx/safe_floor_ceil.h"
+#include "ui/gfx/safe_integer_conversions.h"
 
 namespace gfx {
 
 Size ToFlooredSize(const SizeF& size) {
   int w = ToFlooredInt(size.width());
   int h = ToFlooredInt(size.height());
   return Size(w, h);
 }
 
 Size ToCeiledSize(const SizeF& size) {
   int w = ToCeiledInt(size.width());
   int h = ToCeiledInt(size.height());
   return Size(w, h);
 }
 
 }  // namespace gfx