Backport of
    HADOOP-9405. TestGridmixSummary#testExecutionSummarizer is broken



git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.0.4-alpha@1463292 13f79535-47bb-0310-9956-ffa450edef68
Updating MR CHANGES.txt, as per SVN logs there are not changes in this branch at the moment

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.0.4-alpha@1463324 13f79535-47bb-0310-9956-ffa450edef68