Rewrite media::Pipeline state transition machinery.

media/base/mock_filters.h

Index: media/base/mock_filters.h
diff --git a/media/base/mock_filters.h b/media/base/mock_filters.h
index 3688a95664916942509ca6c49882c98bdc584f20..96a5df6f66b15b297120b0f8910c4228ddc2c03a 100644
--- a/media/base/mock_filters.h
+++ b/media/base/mock_filters.h
@@ -279,17 +279,6 @@ class MockFilterCollection {
   DISALLOW_COPY_AND_ASSIGN(MockFilterCollection);
 };
 
-// Helper gmock action that calls SetError() on behalf of the provided filter.
-ACTION_P2(SetError, filter, error) {
-  filter->host()->SetError(error);
-}
-
-// Helper gmock action that calls SetDuration() on behalf of the provided
-// filter.
-ACTION_P2(SetDuration, filter, duration) {
-  filter->host()->SetDuration(duration);
-}
-
 ACTION(RunClosure) {
   arg0.Run();
 }