Allow HTMLMediaElement.currentTime to be set before the transition to HAVE_METADATA

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 4aeb78fc12c83e7ccae16436395f7b2bc49ef4f5..bb3fbdbae146540b1e8d2f93239dbaf6662cb216 100644
--- a/Source/core/html/HTMLMediaElement.h
+++ b/Source/core/html/HTMLMediaElement.h
@@ -375,7 +375,7 @@ private:
     void startProgressEventTimer();
     void stopPeriodicTimers();
 
-    void seek(double time, ExceptionState&);
+    void seek(double time);
     void finishSeek();
     void checkIfSeekNeeded();
     void addPlayedRange(double start, double end);
@@ -508,6 +508,9 @@ private:
     // The last time a timeupdate event was sent in movie time.
     double m_lastTimeUpdateEventMovieTime;
 
+    // The default playback start position.
+    double m_defaultPlaybackStartPosition;
+
     // Loading state.
     enum LoadState { WaitingForSource, LoadingFromSrcAttr, LoadingFromSourceElement };
     LoadState m_loadState;