Have Node::highestAncestor() return a reference

Source/core/editing/ApplyStyleCommand.cpp

Index: Source/core/editing/ApplyStyleCommand.cpp
diff --git a/Source/core/editing/ApplyStyleCommand.cpp b/Source/core/editing/ApplyStyleCommand.cpp
index d809696167311c30dd9454cb1e7c5325a58bf18d..966eea4a23de22c26d4cc6a017be3c59dd033627 100644
--- a/Source/core/editing/ApplyStyleCommand.cpp
+++ b/Source/core/editing/ApplyStyleCommand.cpp
@@ -253,9 +253,9 @@ void ApplyStyleCommand::applyBlockStyle(EditingStyle *style)
     // Save and restore the selection endpoints using their indices in the document, since
     // addBlockStyleIfNeeded may moveParagraphs, which can remove these endpoints.
     // Calculate start and end indices from the start of the tree that they're in.
-    Node* scope = visibleStart.deepEquivalent().deprecatedNode()->highestAncestor();
-    RefPtr<Range> startRange = Range::create(document(), firstPositionInNode(scope), visibleStart.deepEquivalent().parentAnchoredEquivalent());
-    RefPtr<Range> endRange = Range::create(document(), firstPositionInNode(scope), visibleEnd.deepEquivalent().parentAnchoredEquivalent());
+    Node& scope = visibleStart.deepEquivalent().deprecatedNode()->highestAncestor();
+    RefPtr<Range> startRange = Range::create(document(), firstPositionInNode(&scope), visibleStart.deepEquivalent().parentAnchoredEquivalent());
+    RefPtr<Range> endRange = Range::create(document(), firstPositionInNode(&scope), visibleEnd.deepEquivalent().parentAnchoredEquivalent());
     int startIndex = TextIterator::rangeLength(startRange.get(), true);
     int endIndex = TextIterator::rangeLength(endRange.get(), true);
 
@@ -286,8 +286,8 @@ void ApplyStyleCommand::applyBlockStyle(EditingStyle *style)
         nextParagraphStart = endOfParagraph(paragraphStart).next();
     }
 
-    startRange = PlainTextRange(startIndex).createRangeForSelection(*toContainerNode(scope));
-    endRange = PlainTextRange(endIndex).createRangeForSelection(*toContainerNode(scope));
+    startRange = PlainTextRange(startIndex).createRangeForSelection(toContainerNode(scope));
+    endRange = PlainTextRange(endIndex).createRangeForSelection(toContainerNode(scope));
     if (startRange && endRange)
         updateStartEnd(startRange->startPosition(), endRange->startPosition());
 }