Merge the Sky Engine changes from the SkyDart branch

sky/engine/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 33 matching lines @@
 
     template<size_t inlineCapacity>
     explicit AtomicString(const Vector<UChar, inlineCapacity>& characters)
         : m_string(add(characters.data(), characters.size()))
     {
     }
 
     // Constructing an AtomicString from a String / StringImpl can be expensive if
     // the StringImpl is not already atomic.
     explicit AtomicString(StringImpl* impl) : m_string(add(impl)) { }
-    explicit AtomicString(const String& s) : m_string(add(s.impl())) { }
+    AtomicString(const String& s) : m_string(add(s.impl())) { }
 
     AtomicString(StringImpl* baseString, unsigned start, unsigned length) : m_string(add(baseString, start, length)) { }
 
     enum ConstructFromLiteralTag { ConstructFromLiteral };
     AtomicString(const char* characters, unsigned length, ConstructFromLiteralTag)
         : m_string(addFromLiteralData(characters, length))
     {
     }
 
     template<unsigned charactersCount>
@@ skipping 178 matching lines @@
 
 WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(AtomicString);
 
 using WTF::AtomicString;
 using WTF::nullAtom;
 using WTF::emptyAtom;
 using WTF::starAtom;
 
 #include "sky/engine/wtf/text/StringConcatenate.h"
 #endif  // SKY_ENGINE_WTF_TEXT_ATOMICSTRING_H_