Fix flaky behavior in pipeline teardown.

media/base/pipeline_impl.h

Index: media/base/pipeline_impl.h
diff --git a/media/base/pipeline_impl.h b/media/base/pipeline_impl.h
index 9a217fd80a270335a185880cbb96be845a105804..475cd23636ddb5ee291a659a33adb3edc6af2d4c 100644
--- a/media/base/pipeline_impl.h
+++ b/media/base/pipeline_impl.h
@@ -294,6 +294,9 @@ class PipelineImpl : public Pipeline, public FilterHost {
   // Whether or not the pipeline is perform a stop operation.
   bool tearing_down_;
 
+  // Whether or not an error triggered the teardown.
+  bool error_caused_teardown_;
+
   // Duration of the media in microseconds.  Set by filters.
   base::TimeDelta duration_;