Make calls to AtomicString(const String&) explicit in html/

Source/core/html/track/vtt/VTTParser.cpp

 /*
  * Copyright (C) 2011 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 283 matching lines @@
         String headerValue = line.substring(colonPosition + 1);
         // Steps 12.5.1 - 12.5.11 Region creation: Let region be a new text track region [...]
         createNewRegion(headerValue);
     }
 }
 
 VTTParser::ParseState VTTParser::collectCueId(const String& line)
 {
     if (line.contains("-->"))
         return collectTimingsAndSettings(line);
-    m_currentId = line;
+    m_currentId = AtomicString(line);
     return TimingsAndSettings;
 }
 
 VTTParser::ParseState VTTParser::collectTimingsAndSettings(const String& line)
 {
     // Collect WebVTT cue timings and settings. (5.3 WebVTT cue timings and settings parsing.)
     // Steps 1 - 3 - Let input be the string being parsed and position be a pointer into input.
     unsigned position = 0;
     skipWhiteSpace(line, &position);
 
@@ skipping 117 matching lines @@
     cue->setId(m_currentId);
     cue->parseSettings(m_currentSettings);
 
     m_cuelist.append(cue);
     if (m_client)
         m_client->newCuesParsed();
 }
 
 void VTTParser::resetCueValues()
 {
-    m_currentId = emptyString();
+    m_currentId = emptyAtom;
     m_currentSettings = emptyString();
     m_currentStartTime = 0;
     m_currentEndTime = 0;
     m_currentContent.clear();
 }
 
 void VTTParser::createNewRegion(const String& headerValue)
 {
     if (headerValue.isEmpty())
         return;
@@ skipping 165 matching lines @@
             m_currentNode->parserAppendChild(ProcessingInstruction::create(document, "timestamp", charactersString));
         break;
     }
     default:
         break;
     }
 }
 
 }