Enable WebVTT regions for runtime testing, updated tests and minor fixes

Source/core/html/track/TextTrackRegion.h

Index: Source/core/html/track/TextTrackRegion.h
diff --git a/Source/core/html/track/TextTrackRegion.h b/Source/core/html/track/TextTrackRegion.h
index 04dde0bda9e784b89dd7ebe95aefa99cb74a66df..85186552c14b7954fdb444b3288bb07c7f95afc7 100644
--- a/Source/core/html/track/TextTrackRegion.h
+++ b/Source/core/html/track/TextTrackRegion.h
@@ -31,8 +31,6 @@
 #ifndef TextTrackRegion_h
 #define TextTrackRegion_h
 
-#if ENABLE(WEBVTT_REGIONS)
-
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/dom/Document.h"
 #include "core/html/track/TextTrack.h"
@@ -97,7 +95,7 @@ public:
 
 private:
     TextTrackRegion(ScriptExecutionContext*);
-    Document* ownerDocument() { return toDocument(m_scriptExecutionContext); }
+    Document* ownerDocument() { return toDocument(scriptExecutionContext()); }
 
     void prepareRegionDisplayTree();
 
@@ -160,6 +158,4 @@ private:
 };
 
 } // namespace WebCore
-
-#endif
 #endif