Revert of Out-of-line WTF::String's destructor.

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 53 matching lines @@
 
 // Construct a string with latin1 data, from a null-terminated source.
 String::String(const LChar* characters)
     : m_impl(characters ? StringImpl::create(characters) : nullptr) {}
 
 String::String(const char* characters)
     : m_impl(characters ? StringImpl::create(
                               reinterpret_cast<const LChar*>(characters))
                         : nullptr) {}
 
-String::String(const String&) = default;
-
-String& String::operator=(const String&) = default;
-
-String::String(String&&) = default;
-
-String& String::operator=(String&&) = default;
-
-String::~String() {}
-
 void String::append(const StringView& string) {
   if (string.isEmpty())
     return;
   if (!m_impl) {
     m_impl = string.toString().releaseImpl();
     return;
   }
 
   // FIXME: This is extremely inefficient. So much so that we might want to
   // take this out of String's API. We can make it better by optimizing the
@@ skipping 760 matching lines @@
   }
   buffer.append('\0');
   return buffer;
 }
 
 Vector<char> asciiDebug(String& string) {
   return asciiDebug(string.impl());
 }
 
 #endif