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

ui/gfx/safe_integer_conversions.h

Index: ui/gfx/safe_integer_conversions.h
diff --git a/ui/gfx/safe_floor_ceil.h b/ui/gfx/safe_integer_conversions.h
similarity index 61%
rename from ui/gfx/safe_floor_ceil.h
rename to ui/gfx/safe_integer_conversions.h
index c2d80c6406397c553cb416338cb1c9cea12cbaa8..1cbfb8821f2746cfeb5b6633dae2a31fa8dc8b68 100644
--- a/ui/gfx/safe_floor_ceil.h
+++ b/ui/gfx/safe_integer_conversions.h
@@ -2,15 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef UI_GFX_SAFE_FLOOR_CEIL_H_
-#define UI_GFX_SAFE_FLOOR_CEIL_H_
+#ifndef UI_GFX_SAFE_INTEGER_CONVERSIONS_H_
+#define UI_GFX_SAFE_INTEGER_CONVERSIONS_H_
+
+#include "ui/base/ui_export.h"
 
 namespace gfx {
 
 UI_EXPORT int ClampToInt(float value);
 UI_EXPORT int ToFlooredInt(float value);
 UI_EXPORT int ToCeiledInt(float value);
+UI_EXPORT int ToRoundedInt(float value);
 
 }  // namespace gfx
 
-#endif  // UI_GFX_SAFE_FLOOR_CEIL_H_
+#endif  // UI_GFX_SAFE_INTEGER_CONVERSIONS_H_