Do not convert from RectF to Rect by flooring.

ui/gfx/rect_conversions.h

Index: ui/gfx/rect_conversions.h
diff --git a/ui/gfx/rect_conversions.h b/ui/gfx/rect_conversions.h
new file mode 100644
index 0000000000000000000000000000000000000000..e5f74004353b6692af8d66e152bd01b127893391
--- /dev/null
+++ b/ui/gfx/rect_conversions.h
@@ -0,0 +1,18 @@
+// 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_CONVERSIONS_H_
+#define UI_GFX_RECT_CONVERSIONS_H_
+
+#include "ui/gfx/rect.h"
+#include "ui/gfx/rect_f.h"
+
+namespace gfx {
+
+UI_EXPORT Rect ToEnclosingRect(const RectF& rect);
+UI_EXPORT Rect ToEnclosedRect(const RectF& rect);
+
+}  // namespace gfx
+
+#endif  // UI_GFX_RECT_CONVERSIONS_H_