Wrapped PassRefPtrs in move where passed to RefPtr constructor.

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.
  *
@@ skipping 79 matching lines @@
   String(const char* characters, unsigned length);
 
   // Construct a string with latin1 data, from a null-terminated source.
   String(const LChar* characters)
       : String(reinterpret_cast<const char*>(characters)) {}
   String(const char* characters)
       : String(characters, characters ? strlen(characters) : 0) {}
 
   // Construct a string referencing an existing StringImpl.
   String(StringImpl* impl) : m_impl(impl) {}
-  String(PassRefPtr<StringImpl> impl) : m_impl(impl) {}
+  String(PassRefPtr<StringImpl> impl) : m_impl(std::move(impl)) {}
 
   void swap(String& o) { m_impl.swap(o.m_impl); }
 
   template <typename CharType>
   static String adopt(StringBuffer<CharType>& buffer) {
     if (!buffer.length())
       return StringImpl::empty;
     return String(buffer.release());
   }
 
@@ skipping 486 matching lines @@
 using WTF::String;
 using WTF::emptyString;
 using WTF::emptyString16Bit;
 using WTF::charactersAreAllASCII;
 using WTF::equal;
 using WTF::find;
 using WTF::isSpaceOrNewline;
 
 #include "wtf/text/AtomicString.h"
 #endif  // WTFString_h