Introduce firstRangeOf() as replacement of VisibleSelection::firstRange()

Source/core/editing/VisibleSelection.h

 /*
  * Copyright (C) 2004 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 134 matching lines @@
 
     bool isBaseFirst() const { return m_baseIsFirst; }
     bool isDirectional() const { return m_isDirectional; }
     void setIsDirectional(bool isDirectional) { m_isDirectional = isDirectional; }
 
     void appendTrailingWhitespace();
 
     bool expandUsingGranularity(TextGranularity);
     bool expandUsingGranularityInComposedTree(TextGranularity);
 
-    // We don't yet support multi-range selections, so we only ever have one range to return.
-    PassRefPtrWillBeRawPtr<Range> firstRange() const;
-
     bool intersectsNode(Node*) const;
 
     // FIXME: Most callers probably don't want these functions, but
     // are using them for historical reasons. toNormalizedRange and
     // toNormalizedEphemeralRange contracts the range around text, and
     // moves the caret upstream before returning the range/positions.
     PassRefPtrWillBeRawPtr<Range> toNormalizedRange() const;
     EphemeralRange toNormalizedEphemeralRange() const;
     static EphemeralRange normalizeRange(const EphemeralRange&);
     static EphemeralRangeInComposedTree normalizeRange(const EphemeralRangeInComposedTree&);
@@ skipping 82 matching lines @@
     // Oilpan: this reference has a lifetime that is at least as long
     // as this object.
     RawPtrWillBeMember<ChangeObserver> m_changeObserver;
 
     // these are cached, can be recalculated by validate()
     SelectionType m_selectionType; // None, Caret, Range
     bool m_baseIsFirst : 1; // True if base is before the extent
     bool m_isDirectional : 1; // Non-directional ignores m_baseIsFirst and selection always extends on shift + arrow key.
 };
 
+// We don't yet support multi-range selections, so we only ever have one range
+// to return.
+CORE_EXPORT PassRefPtrWillBeRawPtr<Range> firstRangeOf(const VisibleSelection&);
+
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::VisibleSelection&);
 void showTree(const blink::VisibleSelection*);
 #endif
 
 #endif // VisibleSelection_h