Utilize EphemeralRange::commonAncestorContainer in createStyleAtSelectionStart

third_party/WebKit/Source/core/editing/EditingStyleUtilities.cpp

Index: third_party/WebKit/Source/core/editing/EditingStyleUtilities.cpp
diff --git a/third_party/WebKit/Source/core/editing/EditingStyleUtilities.cpp b/third_party/WebKit/Source/core/editing/EditingStyleUtilities.cpp
index 1c72d9b452487d87e062b1f1395fbc785e1379be..9822f5433456b1641c86ad0d8600eba9eb2edf80 100644
--- a/third_party/WebKit/Source/core/editing/EditingStyleUtilities.cpp
+++ b/third_party/WebKit/Source/core/editing/EditingStyleUtilities.cpp
@@ -148,9 +148,7 @@ EditingStyle* EditingStyleUtilities::createStyleAtSelectionStart(
       (selection.isRange() || hasTransparentBackgroundColor(style->style()))) {
     const EphemeralRange range(selection.toNormalizedEphemeralRange());
     if (const CSSValue* value =
-            backgroundColorValueInEffect(Range::commonAncestorContainer(
-                range.startPosition().computeContainerNode(),
-                range.endPosition().computeContainerNode())))
+            backgroundColorValueInEffect(range.commonAncestorContainer()))
       style->setProperty(CSSPropertyBackgroundColor, value->cssText());
   }