Use VTTScanner for VTT cue settings parsing

Source/core/html/track/vtt/VTTCue.h

 /*
  * Copyright (c) 2013, Opera Software ASA. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 20 matching lines @@
 #define VTTCue_h
 
 #include "bindings/v8/ScriptWrappable.h"
 #include "core/html/track/TextTrackCue.h"
 
 namespace WebCore {
 
 class Document;
 class ExecutionContext;
 class VTTCue;
+class VTTScanner;
 
 class VTTCueBox FINAL : public HTMLDivElement {
 public:
     static PassRefPtr<VTTCueBox> create(Document& document, VTTCue* cue)
     {
         return adoptRef(new VTTCueBox(document, cue));
     }
 
     VTTCue* getCue() const { return m_cue; }
     void applyCSSProperties(const IntSize& videoSize);
@@ skipping 104 matching lines @@
 
     enum CueSetting {
         None,
         Vertical,
         Line,
         Position,
         Size,
         Align,
         RegionId
     };
-    CueSetting settingName(const String&);
+    CueSetting settingName(VTTScanner&);
 
     String m_text;
     int m_linePosition;
     int m_computedLinePosition;
     int m_textPosition;
     int m_cueSize;
     WritingDirection m_writingDirection;
     CueAlignment m_cueAlignment;
     String m_regionId;
 
     RefPtr<DocumentFragment> m_vttNodeTree;
     RefPtr<HTMLDivElement> m_cueBackgroundBox;
     RefPtr<VTTCueBox> m_displayTree;
 
     CSSValueID m_displayDirection;
     int m_displaySize;
     std::pair<float, float> m_displayPosition;
 
     bool m_snapToLines : 1;
     bool m_displayTreeShouldChange : 1;
     bool m_notifyRegion : 1;
 };
 
 // VTTCue is currently the only TextTrackCue subclass.
 DEFINE_TYPE_CASTS(VTTCue, TextTrackCue, cue, true, true);
 
 } // namespace WebCore
 
 #endif