Utilize EphemeralRange::commonAncestorContainer in createStyleAtSelectionStart

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

 /*
  * Copyright (C) 2007, 2008, 2009 Apple Computer, Inc.
  * Copyright (C) 2010, 2011 Google 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
@@ skipping 130 matching lines @@
   }
 
   // If background color is transparent, traverse parent nodes until we hit a
   // different value or document root Also, if the selection is a range, ignore
   // the background color at the start of selection, and find the background
   // color of the common ancestor.
   if (shouldUseBackgroundColorInEffect &&
       (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());
   }
 
   return style;
 }
 
 static bool isUnicodeBidiNestedOrMultipleEmbeddings(CSSValueID valueID) {
   return valueID == CSSValueEmbed || valueID == CSSValueBidiOverride ||
          valueID == CSSValueWebkitIsolate ||
          valueID == CSSValueWebkitIsolateOverride ||
@@ skipping 133 matching lines @@
   for (Node* ancestor = node; ancestor; ancestor = ancestor->parentNode()) {
     CSSComputedStyleDeclaration* ancestorStyle =
         CSSComputedStyleDeclaration::create(ancestor);
     if (!hasTransparentBackgroundColor(ancestorStyle))
       return ancestorStyle->getPropertyCSSValue(CSSPropertyBackgroundColor);
   }
   return nullptr;
 }
 
 }  // namespace blink