VTTCue: Support 'auto' for line

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 18 matching lines @@
 
 #ifndef VTTCue_h
 #define VTTCue_h
 
 #include "core/html/track/TextTrackCue.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class Document;
+class DoubleOrAutoKeyword;
 class ExecutionContext;
 class VTTCue;
 class VTTScanner;
 
 class VTTCueBox final : public HTMLDivElement {
 public:
     static PassRefPtrWillBeRawPtr<VTTCueBox> create(Document& document, VTTCue* cue)
     {
         return adoptRefWillBeNoop(new VTTCueBox(document, cue));
     }
@@ skipping 20 matching lines @@
     }
 
     virtual ~VTTCue();
 
     const String& vertical() const;
     void setVertical(const String&);
 
     bool snapToLines() const { return m_snapToLines; }
     void setSnapToLines(bool);
 
-    double line() const { return m_linePosition; }
-    void setLine(double, ExceptionState&);
+    void line(DoubleOrAutoKeyword&) const;
+    void setLine(const DoubleOrAutoKeyword&);
 
     double position() const { return m_textPosition; }
     void setPosition(double, ExceptionState&);
 
     double size() const { return m_cueSize; }
     void setSize(double, ExceptionState&);
 
     const String& align() const;
     void setAlign(const String&);
 
@@ skipping 90 matching lines @@
 
     RefPtrWillBeMember<DocumentFragment> m_vttNodeTree;
     RefPtrWillBeMember<HTMLDivElement> m_cueBackgroundBox;
     RefPtrWillBeMember<VTTCueBox> m_displayTree;
 
     CSSValueID m_displayDirection;
     float m_displaySize;
     FloatPoint m_displayPosition;
 
     bool m_snapToLines : 1;
+    bool m_lineIsAuto : 1;

[philipj_slow, 2015/01/20 14:52:31]

How about using NaN for auto? Too clever?

[fs, 2015/01/20 16:35:16]

I considered it, but since this is equally "free" storage-wise and felt slightly
more readable in places (since we can't compare NaN == NaN in the setter for
instance). that way certainly has it's allure though, so I'll code it up and see
what I think in practice...

Uploaded as PS3 for your viewing pleasure.

     bool m_displayTreeShouldChange : 1;
     bool m_notifyRegion : 1;
 };
 
 // VTTCue is currently the only TextTrackCue subclass.
 DEFINE_TYPE_CASTS(VTTCue, TextTrackCue, cue, true, true);
 
 } // namespace blink
 
 #endif // VTTCue_h