Make PipelineImpl state change tasks consistent.

media/base/pipeline_impl_unittest.cc

Index: media/base/pipeline_impl_unittest.cc
diff --git a/media/base/pipeline_impl_unittest.cc b/media/base/pipeline_impl_unittest.cc
index 6333e8dcd274622521afea8abdcfad613e3b9304..661830c673f92fb08b77d640445f569d9c9bdc90 100644
--- a/media/base/pipeline_impl_unittest.cc
+++ b/media/base/pipeline_impl_unittest.cc
@@ -898,15 +898,14 @@ class PipelineTeardownTest : public PipelineImplTest {
         EXPECT_CALL(*renderer_, Initialize(_, _, _))
             .WillOnce(
                 DoAll(Stop(pipeline_.get()), PostCallback<2>(PIPELINE_OK)));
-        // Note: OnStart or OnMetadata callback are not called
-        // after pipeline is stopped.
+        // Note: OnStart is not callback after pipeline is stopped.
       } else {
         EXPECT_CALL(*renderer_, Initialize(_, _, _))
             .WillOnce(PostCallback<2>(PIPELINE_ERROR_INITIALIZATION_FAILED));
-        EXPECT_CALL(callbacks_, OnMetadata(_));
         EXPECT_CALL(callbacks_, OnStart(PIPELINE_ERROR_INITIALIZATION_FAILED));
       }
 
+      EXPECT_CALL(callbacks_, OnMetadata(_));
       EXPECT_CALL(*demuxer_, Stop());
       return;
     }