Both the trunk and the branch_3x Jenkins Maven builds failed last night because the Maven configuration for the solr/contrib/extraction/ module does not depend on solr-core test code, and you just introduced a new solr-core test class BufferingRequestProcessor, as well as test code in Solr Cell that uses this class.
(BTW, none of the other Solr modules depend on Solr test code in the Maven configuration.)
Apparently the Ant build system still includes solr-core test classes in the test classpath of the other Solr modules. I think this should be fixed; Solr's test-framework makes this dependency obsolete.
In the short term, though, can we move the new BufferingRequestProcessor class from solr/core/src/test to solr/test-framework/src/java/? That way, the Maven stuff will work again without having to jump through hoops like publishing a solr-core test jar and making other modules have a test dependency on it (that's the way it worked pre-test-framework).