Implement VTTCue.region and sync the VTTRegion interface

third_party/WebKit/Source/core/html/track/vtt/VTTRegion.h

Index: third_party/WebKit/Source/core/html/track/vtt/VTTRegion.h
diff --git a/third_party/WebKit/Source/core/html/track/vtt/VTTRegion.h b/third_party/WebKit/Source/core/html/track/vtt/VTTRegion.h
index 4ec0baf723c847f19d727c115bb4ef4ad5ed9606..a78c1cef9092d0b09c0f1c9ee0872248491eaba0 100644
--- a/third_party/WebKit/Source/core/html/track/vtt/VTTRegion.h
+++ b/third_party/WebKit/Source/core/html/track/vtt/VTTRegion.h
@@ -33,7 +33,6 @@
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/dom/ContextLifecycleObserver.h"
-#include "core/html/track/TextTrack.h"
 #include "platform/Timer.h"
 #include "platform/geometry/FloatPoint.h"
 #include "platform/heap/Handle.h"
@@ -55,17 +54,14 @@ class VTTRegion final : public GarbageCollectedFinalized<VTTRegion>,
 
   virtual ~VTTRegion();
 
-  TextTrack* track() const { return m_track; }
-  void setTrack(TextTrack*);
-
   const String& id() const { return m_id; }
   void setId(const String&);
 
   double width() const { return m_width; }
   void setWidth(double, ExceptionState&);
 
-  long height() const { return m_heightInLines; }
-  void setHeight(long, ExceptionState&);
+  long lines() const { return m_lines; }
+  void setLines(long, ExceptionState&);
 
   double regionAnchorX() const { return m_regionAnchor.x(); }
   void setRegionAnchorX(double, ExceptionState&);
@@ -80,7 +76,7 @@ class VTTRegion final : public GarbageCollectedFinalized<VTTRegion>,
   void setViewportAnchorY(double, ExceptionState&);
 
   const AtomicString scroll() const;
-  void setScroll(const AtomicString&, ExceptionState&);
+  void setScroll(const AtomicString&);
 
   void updateParametersFromRegion(VTTRegion*);
 
@@ -126,7 +122,7 @@ class VTTRegion final : public GarbageCollectedFinalized<VTTRegion>,
   String m_id;
   String m_settings;
   double m_width;
-  unsigned m_heightInLines;
+  unsigned m_lines;
   FloatPoint m_regionAnchor;
   FloatPoint m_viewportAnchor;
   bool m_scroll;
@@ -136,12 +132,6 @@ class VTTRegion final : public GarbageCollectedFinalized<VTTRegion>,
   Member<HTMLDivElement> m_cueContainer;
   Member<HTMLDivElement> m_regionDisplayTree;
 
-  // The member variable track can be a raw pointer as it will never
-  // reference a destroyed TextTrack, as this member variable
-  // is cleared in the TextTrack destructor and it is generally
-  // set/reset within the addRegion and removeRegion methods.
-  Member<TextTrack> m_track;
-
   // Keep track of the current numeric value of the css "top" property.
   double m_currentTop;