Bug 865407 - Part 4: Expose TextTrackCue::DisplayState to chrome JS. r=rillian, r=bz

content/media/TextTrackCue.cpp

@@ -104,12 +104,13 @@ TextTrackCue::StashDocument(nsISupports* aGlobal)
 void
 TextTrackCue::CreateCueOverlay()
 {
-  mDocument->CreateElem(NS_LITERAL_STRING("div"), nullptr,
-                        kNameSpaceID_XHTML,
-                        getter_AddRefs(mDisplayState));
-  nsGenericHTMLElement* cueDiv =
-    static_cast<nsGenericHTMLElement*>(mDisplayState.get());
-  cueDiv->SetClassName(NS_LITERAL_STRING("caption-text"));
+  nsCOMPtr<nsINodeInfo> nodeInfo =
+    mDocument->NodeInfoManager()->GetNodeInfo(nsGkAtoms::div,
+                                              nullptr,
+                                              kNameSpaceID_XHTML,
+                                              nsIDOMNode::ELEMENT_NODE);
+  mDisplayState = NS_NewHTMLDivElement(nodeInfo.forget());
+  mDisplayState->SetClassName(NS_LITERAL_STRING("caption-text"));
 }
 
 void
@@ -148,7 +149,7 @@ TextTrackCue::RenderCue()
   nsContentUtils::SetNodeTextContent(overlay, EmptyString(), true);
   nsContentUtils::SetNodeTextContent(mDisplayState, EmptyString(), true);
 
-  mDisplayState->AppendChild(*frag, rv);
+  mDisplayState->nsINode::AppendChild(*frag, rv);
   overlay->AppendChild(*mDisplayState, rv);
 }
 

content/media/TextTrackCue.h

@@ -14,6 +14,7 @@
 #include "nsIWebVTTParserWrapper.h"
 #include "mozilla/StaticPtr.h"
 #include "nsIDocument.h"
+#include "mozilla/dom/HTMLDivElement.h"
 
 namespace mozilla {
 namespace dom {
@@ -296,6 +297,16 @@ public:
   IMPL_EVENT_HANDLER(enter)
   IMPL_EVENT_HANDLER(exit)
 
+  HTMLDivElement* GetDisplayState()
+  {
+    return static_cast<HTMLDivElement*>(mDisplayState.get());
+  }
+
+  void SetDisplayState(HTMLDivElement* aDisplayState)
+  {
+    mDisplayState = aDisplayState;
+  }
+
   // Helper functions for implementation.
   bool
   operator==(const TextTrackCue& rhs) const
@@ -376,7 +387,7 @@ private:
 
   // Holds the computed DOM elements that represent the parsed cue text.
   // http://www.whatwg.org/specs/web-apps/current-work/#text-track-cue-display-state
-  nsCOMPtr<nsIContent> mDisplayState;
+  nsRefPtr<nsGenericHTMLElement> mDisplayState;
   // Tells whether or not we need to recompute mDisplayState. This is set
   // anytime a property that relates to the display of the TextTrackCue is
   // changed.

dom/webidl/VTTCue.webidl

@@ -53,3 +53,9 @@ interface VTTCue : EventTarget {
 
   attribute EventHandler onexit;
 };
+
+// Mozilla extensions.
+partial interface VTTCue {
+  [ChromeOnly]
+  attribute HTMLDivElement? displayState;
+};