Literal AtomicString construction can rely on strlen optimization.

third_party/WebKit/Source/core/html/HTMLProgressElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * 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 132 matching lines @@
         if (wasDeterminate != isDeterminate())
             pseudoStateChanged(CSSSelector::PseudoIndeterminate);
     }
 }
 
 void HTMLProgressElement::didAddUserAgentShadowRoot(ShadowRoot& root)
 {
     ASSERT(!m_value);
 
     RefPtrWillBeRawPtr<ProgressInnerElement> inner = ProgressInnerElement::create(document());
-    inner->setShadowPseudoId(AtomicString("-webkit-progress-inner-element", AtomicString::ConstructFromLiteral));
+    inner->setShadowPseudoId(AtomicString("-webkit-progress-inner-element"));
     root.appendChild(inner);
 
     RefPtrWillBeRawPtr<ProgressBarElement> bar = ProgressBarElement::create(document());
-    bar->setShadowPseudoId(AtomicString("-webkit-progress-bar", AtomicString::ConstructFromLiteral));
+    bar->setShadowPseudoId(AtomicString("-webkit-progress-bar"));
     RefPtrWillBeRawPtr<ProgressValueElement> value = ProgressValueElement::create(document());
     m_value = value.get();
-    m_value->setShadowPseudoId(AtomicString("-webkit-progress-value", AtomicString::ConstructFromLiteral));
+    m_value->setShadowPseudoId(AtomicString("-webkit-progress-value"));
     m_value->setWidthPercentage(HTMLProgressElement::IndeterminatePosition * 100);
     bar->appendChild(m_value);
 
     inner->appendChild(bar);
 }
 
 bool HTMLProgressElement::shouldAppearIndeterminate() const
 {
     return !isDeterminate();
 }
 
 DEFINE_TRACE(HTMLProgressElement)
 {
     visitor->trace(m_value);
     LabelableElement::trace(visitor);
 }
 
 } // namespace blink