Do not convert from RectF to Rect by flooring.

ui/gfx/rect_f.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/rect_f.h"
 
 #include "base/logging.h"
 #include "base/stringprintf.h"
 #include "ui/gfx/insets_f.h"
 #include "ui/gfx/rect_base_impl.h"
@@ skipping 18 matching lines @@
 RectF::RectF(const gfx::SizeF& size)
     : RectBaseT(size) {
 }
 
 RectF::RectF(const gfx::PointF& origin, const gfx::SizeF& size)
     : RectBaseT(origin, size) {
 }
 
 RectF::~RectF() {}
 
-Rect RectF::ToRect() const {
-  return Rect(origin().ToPoint(), size().ToSize());
-}
-
 std::string RectF::ToString() const {
   return base::StringPrintf("%s %s",
                             origin().ToString().c_str(),
                             size().ToString().c_str());
 }
 
 }  // namespace gfx