Introduce firstEphemeralRangeOf().

Source/core/editing/InputMethodController.cpp

Index: Source/core/editing/InputMethodController.cpp
diff --git a/Source/core/editing/InputMethodController.cpp b/Source/core/editing/InputMethodController.cpp
index 3c695f1e8270c7f1baf763f8e3825d031e9a2993..3c5a07856361785edbd4baa11e8cd1ed54481617 100644
--- a/Source/core/editing/InputMethodController.cpp
+++ b/Source/core/editing/InputMethodController.cpp
@@ -359,12 +359,12 @@ PassRefPtrWillBeRawPtr<Range> InputMethodController::compositionRange() const
 
 PlainTextRange InputMethodController::getSelectionOffsets() const
 {
-    RefPtrWillBeRawPtr<Range> range = firstRangeOf(frame().selection().selection());
-    if (!range)
+    EphemeralRange range = firstEphemeralRangeOf(frame().selection().selection());
+    if (range.isNull())
         return PlainTextRange();
     ContainerNode* editable = frame().selection().rootEditableElementOrTreeScopeRootNode();
     ASSERT(editable);
-    return PlainTextRange::create(*editable, *range.get());
+    return PlainTextRange::create(*editable, range);
 }
 
 bool InputMethodController::setSelectionOffsets(const PlainTextRange& selectionOffsets)