Implement HTMLMediaElement::srcObject.

Source/core/html/HTMLMediaElement.h

Index: Source/core/html/HTMLMediaElement.h
diff --git a/Source/core/html/HTMLMediaElement.h b/Source/core/html/HTMLMediaElement.h
index e1706610fe53f2519267eaa2daa3379d166dd87a..d472f3e78b63f9496cd96d504d788e42b073956f 100644
--- a/Source/core/html/HTMLMediaElement.h
+++ b/Source/core/html/HTMLMediaElement.h
@@ -59,6 +59,7 @@ class HTMLTrackElement;
 class KURL;
 class MediaController;
 class MediaControls;
+class MediaProvider;
 class MediaError;
 class HTMLMediaSource;
 class TextTrackList;
@@ -111,6 +112,8 @@ public:
 
     // network state
     void setSrc(const AtomicString&);
+    void setSrcObject(RawPtr<MediaProvider>);
+    MediaProvider* srcObject() const;
     const KURL& currentSrc() const { return m_currentSrc; }
 
     enum NetworkState { NETWORK_EMPTY, NETWORK_IDLE, NETWORK_LOADING, NETWORK_NO_SOURCE };
@@ -389,6 +392,8 @@ private:
     void setPlayerPreload();
     blink::WebMediaPlayer::LoadType loadType() const;
     void scheduleNextSourceChild();
+    void loadSourceFromObject();
+    void loadSourceFromAttribute();
     void loadNextSourceChild();
     void userCancelledLoad();
     void clearMediaPlayer(int flags);
@@ -506,8 +511,9 @@ private:
     double m_defaultPlaybackStartPosition;
 
     // Loading state.
-    enum LoadState { WaitingForSource, LoadingFromSrcAttr, LoadingFromSourceElement };
+    enum LoadState { WaitingForSource, LoadingFromSrcObject, LoadingFromSrcAttr, LoadingFromSourceElement };
     LoadState m_loadState;
+    RawPtrWillBeMember<MediaProvider> m_srcObject;
     RefPtrWillBeMember<HTMLSourceElement> m_currentSourceNode;
     RefPtrWillBeMember<Node> m_nextChildNodeToConsider;