Use StringView for String::find.

third_party/WebKit/Source/wtf/text/AtomicString.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 61 matching lines @@
     unsigned length() const { return m_string.length(); }
 
     UChar operator[](unsigned i) const { return m_string[i]; }
 
     bool contains(UChar c) const { return m_string.contains(c); }
     bool contains(const LChar* s, TextCaseSensitivity caseSensitivity = TextCaseSensitive) const
         { return m_string.contains(s, caseSensitivity); }
     bool contains(const String& s, TextCaseSensitivity caseSensitivity = TextCaseSensitive) const
         { return m_string.contains(s, caseSensitivity); }
 
-    size_t find(UChar c, size_t start = 0) const { return m_string.find(c, start); }
+    // Find characters.
+    size_t find(UChar c, unsigned start = 0) const
+        { return m_string.find(c, start); }
+    size_t find(LChar c, unsigned start = 0) const
+        { return m_string.find(c, start); }
+    size_t find(char c, unsigned start = 0) const { return find(static_cast<LChar>(c), start); }
     size_t find(CharacterMatchFunctionPtr matchFunction, unsigned start = 0) const
         { return m_string.find(matchFunction, start); }
-    size_t find(const LChar* s, size_t start = 0, TextCaseSensitivity caseSensitivity = TextCaseSensitive) const
-        { return m_string.find(s, start, caseSensitivity); }
-    size_t find(const String& s, size_t start = 0, TextCaseSensitivity caseSensitivity = TextCaseSensitive) const
-        { return m_string.find(s, start, caseSensitivity); }
+
+    // Find substrings.
+    size_t find(const StringView& value, unsigned start = 0, TextCaseSensitivity caseSensitivity = TextCaseSensitive) const
+        { return m_string.find(value, start, caseSensitivity); }
 
     bool startsWith(const StringView& prefix, TextCaseSensitivity caseSensitivity = TextCaseSensitive) const
         { return m_string.startsWith(prefix, caseSensitivity); }
     bool startsWith(UChar character) const
         { return m_string.startsWith(character); }
 
     bool endsWith(const StringView& suffix, TextCaseSensitivity caseSensitivity = TextCaseSensitive) const
         { return m_string.endsWith(suffix, caseSensitivity); }
     bool endsWith(UChar character) const
         { return m_string.endsWith(character); }
@@ skipping 105 matching lines @@
 using WTF::AtomicString;
 using WTF::nullAtom;
 using WTF::emptyAtom;
 using WTF::starAtom;
 using WTF::xmlAtom;
 using WTF::xmlnsAtom;
 using WTF::xlinkAtom;
 
 #include "wtf/text/StringConcatenate.h"
 #endif // AtomicString_h