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 7c0acbcd7817fab0558cacc6cfd06f04c3344f78..91f5f639b11136fd2590b40baf584ff8112b68ba 100644
--- a/Source/core/html/HTMLMediaElement.h
+++ b/Source/core/html/HTMLMediaElement.h
@@ -376,7 +376,7 @@ private:
     void startProgressEventTimer();
     void stopPeriodicTimers();
 
-    void seek(double time, ExceptionState&);
+    void seek(double time);
     void finishSeek();
     void checkIfSeekNeeded();
     void addPlayedRange(double start, double end);
@@ -509,6 +509,9 @@ 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;