Move NG floats utility methods to the separate file

third_party/WebKit/Source/core/layout/ng/ng_floats_utils.h

+// Copyright 2017 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 NGFloatsUtils_h
+#define NGFloatsUtils_h
+
+#include "core/layout/ng/geometry/ng_logical_offset.h"
+#include "core/layout/ng/ng_constraint_space.h"
+#include "core/layout/ng/ng_floating_object.h"
+
+namespace blink {
+
+// Calculates the relative position from {@code from_offset} of the
+// floating object that is requested to be positioned from {@code origin_point}.
+CORE_EXPORT NGLogicalOffset PositionFloat(const NGLogicalOffset& origin_point,
+                                          const NGLogicalOffset& from_offset,
+                                          NGFloatingObject*,
+                                          NGConstraintSpace* new_parent_space);
+
+}  // namespace blink
+
+#endif  // NGFloatsUtils_h