Fixes play seek when user sets loop after ended.

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 6f539a0bd30757c50c9e939d57f7547960ee2ceb..4874cde5959676cb8f2d6176c89915a6c2c371ff 100644
--- a/Source/core/html/HTMLMediaElement.h
+++ b/Source/core/html/HTMLMediaElement.h
@@ -411,10 +411,15 @@ private:
     void updateVolume();
     void updatePlayState();
     bool potentiallyPlaying() const;
-    bool endedPlayback() const;
     bool stoppedDueToErrors() const;
     bool couldPlayIfEnoughData() const;
 
+    // Generally the presence of the loop attribute should be considered to mean playback
+    // has not "ended", as "ended" and "looping" are mutually exclusive. See
+    // https://html.spec.whatwg.org/multipage/embedded-content.html#ended-playback
+    enum class LoopCondition { Included, Ignored };
+    bool endedPlayback(LoopCondition = LoopCondition::Included) const;
+
     void setShouldDelayLoadEvent(bool);
     void invalidateCachedTime();
     void refreshCachedTime() const;