Introduce createRange(const EphemeralRange&)

Source/core/editing/EphemeralRange.h

Index: Source/core/editing/EphemeralRange.h
diff --git a/Source/core/editing/EphemeralRange.h b/Source/core/editing/EphemeralRange.h
index c4f280268b2ea62537543c096346c017ae5148a6..b8daf06b4f6bf61207a170fb8b19de9b027f712e 100644
--- a/Source/core/editing/EphemeralRange.h
+++ b/Source/core/editing/EphemeralRange.h
@@ -87,6 +87,10 @@ using EphemeralRange = EphemeralRangeTemplate<EditingStrategy>;
 extern template class CORE_EXTERN_TEMPLATE_EXPORT EphemeralRangeTemplate<EditingInComposedTreeStrategy>;
 using EphemeralRangeInComposedTree = EphemeralRangeTemplate<EditingInComposedTreeStrategy>;
 
+// Returns a newly created |Range| object from |range| or |nullptr| if
+// |range.isNull()| returns true.
+CORE_EXPORT PassRefPtrWillBeRawPtr<Range> createRange(const EphemeralRange& /* range */);
+
 } // namespace blink
 
 #endif