Literal AtomicString construction can rely on strlen optimization.

third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 123 matching lines @@
     ASSERT(isRemoved());
     ASSERT(!m_loader);
     ASSERT(!m_stream);
     ASSERT(!m_webSourceBuffer);
 #endif
     WTF_LOG(Media, "SourceBuffer(%p)::~SourceBuffer", this);
 }
 
 const AtomicString& SourceBuffer::segmentsKeyword()
 {
-    DEFINE_STATIC_LOCAL(const AtomicString, segments, ("segments", AtomicString::ConstructFromLiteral));
+    DEFINE_STATIC_LOCAL(const AtomicString, segments, ("segments"));
     return segments;
 }
 
 const AtomicString& SourceBuffer::sequenceKeyword()
 {
-    DEFINE_STATIC_LOCAL(const AtomicString, sequence, ("sequence", AtomicString::ConstructFromLiteral));
+    DEFINE_STATIC_LOCAL(const AtomicString, sequence, ("sequence"));
     return sequence;
 }
 
 void SourceBuffer::setMode(const AtomicString& newMode, ExceptionState& exceptionState)
 {
     WTF_LOG(Media, "SourceBuffer::setMode %p newMode=%s", this, newMode.utf8().data());
     // Section 3.1 On setting mode attribute steps.
     // 1. Let new mode equal the new value being assigned to this attribute.
     // 2. If this object has been removed from the sourceBuffers attribute of the parent media source, then throw
     //    an INVALID_STATE_ERR exception and abort these steps.
@@ skipping 710 matching lines @@
     visitor->trace(m_asyncEventQueue);
     visitor->trace(m_appendBufferAsyncPartRunner);
     visitor->trace(m_removeAsyncPartRunner);
     visitor->trace(m_appendStreamAsyncPartRunner);
     visitor->trace(m_stream);
     RefCountedGarbageCollectedEventTargetWithInlineData<SourceBuffer>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink