Use StringView for String::split.

third_party/WebKit/Source/wtf/text/WTFString.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010, 2012 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 478 matching lines @@
 String String::isolatedCopy() const {
   if (!m_impl)
     return String();
   return m_impl->isolatedCopy();
 }
 
 bool String::isSafeToSendToAnotherThread() const {
   return !m_impl || m_impl->isSafeToSendToAnotherThread();
 }
 
-void String::split(const String& separator,
+void String::split(const StringView& separator,
                    bool allowEmptyEntries,
                    Vector<String>& result) const {
   result.clear();
 
   unsigned startPos = 0;
   size_t endPos;
   while ((endPos = find(separator, startPos)) != kNotFound) {
     if (allowEmptyEntries || startPos != endPos)
       result.append(substring(startPos, endPos - startPos));
     startPos = endPos + separator.length();
@@ skipping 336 matching lines @@
   }
   buffer.append('\0');
   return buffer;
 }
 
 Vector<char> asciiDebug(String& string) {
   return asciiDebug(string.impl());
 }
 
 #endif