Add toStdString methods to CString and WTF::String

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

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 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,
@@ skipping 15 matching lines @@
 // on systems without case-sensitive file systems.
 
 #include "wtf/HashTableDeletedValueType.h"
 #include "wtf/WTFExport.h"
 #include "wtf/testing/WTFUnitTestHelpersExport.h"
 #include "wtf/text/ASCIIFastPath.h"
 #include "wtf/text/StringImpl.h"
 #include "wtf/text/StringView.h"
 #include <algorithm>
 #include <iosfwd>
+#include <string>
 
 #ifdef __OBJC__
 #include <objc/objc.h>
 #endif
 
 namespace WTF {
 
 class CString;
 struct StringHash;
 
@@ skipping 126 matching lines @@
     {
         if (!m_impl)
             return 0;
         return m_impl->length() * (is8Bit() ? sizeof(LChar) : sizeof(UChar));
     }
 
     CString ascii() const;
     CString latin1() const;
     CString utf8(UTF8ConversionMode = LenientUTF8Conversion) const;
 
+    std::string toUTF8() const;

[esprehn, 2015/09/30 18:15:39]

This is confusing with the .utf8() method. I'm also hesitant to do this yet, we
shouldn't be using std::string in almost all blink code.

[tkent, 2015/10/01 02:09:06]

At least, the function should have a document that we should use it only to pass
stings to Chromium.

[Primiano Tucci (use gerrit), 2015/10/01 07:34:51]

So, what is the final take? keep it and document? Or rely on
utf8().toStdString() ?
I think we need to come up with a decision here.
Is there the possibility that in future WTFString.toStdString() could do
something smarter (read: more efficient) than utf8().toStdString() ?
If so I think we should go for keeping here and documenting as tkent suggested.

+
     UChar operator[](unsigned index) const
     {
         if (!m_impl || index >= m_impl->length())
             return 0;
         return (*m_impl)[index];
     }
 
     static String number(int);
     static String number(unsigned);
     static String number(long);
@@ skipping 506 matching lines @@
 using WTF::charactersToFloat;
 using WTF::equal;
 using WTF::equalIgnoringCase;
 using WTF::find;
 using WTF::isAllSpecialCharacters;
 using WTF::isSpaceOrNewline;
 using WTF::reverseFind;
 
 #include "wtf/text/AtomicString.h"
 #endif // WTFString_h