Revert "Revert "HBASE-16983 TestMultiTableSnapshotInputFormat failing with Unable to create region directory: /tmp/... (Addendum by Guanghao Zhang)""

This is a revert of a revert, i.e. puts back the change only I added
HBaseCommonTestingUtility#getRandomDir from branch-1 too since
missing in master branch.

This reverts commit 9afcb4366d.

hbase-common/src/test/java/org/apache/hadoop/hbase/HBaseCommonTestingUtility.java

@@ -108,10 +108,7 @@ public class HBaseCommonTestingUtility {
           dataTestDir.getAbsolutePath());
       return null;
     }
-
-    String randomStr = UUID.randomUUID().toString();
-    Path testPath = new Path(getBaseTestDir(), randomStr);
-
+    Path testPath = getRandomDir();
     this.dataTestDir = new File(testPath.toString()).getAbsoluteFile();
     // Set this property so if mapreduce jobs run, they will use this as their home dir.
     System.setProperty("test.build.dir", this.dataTestDir.toString());
@@ -122,6 +119,14 @@ public class HBaseCommonTestingUtility {
     return testPath;
   }
 
+  /**
+   * @return A dir with a random (uuid) name under the test dir
+   * @see #getBaseTestDir()
+   */
+  public Path getRandomDir() {
+    return new Path(getBaseTestDir(), UUID.randomUUID().toString());
+  }
+
   protected void createSubDir(String propertyName, Path parent, String subDirName) {
     Path newPath = new Path(parent, subDirName);
     File newDir = new File(newPath.toString()).getAbsoluteFile();

hbase-server/src/test/java/org/apache/hadoop/hbase/mapreduce/TestMultiTableSnapshotInputFormat.java

@@ -64,8 +64,7 @@ public class TestMultiTableSnapshotInputFormat extends MultiTableInputFormatTest
 
   @Before
   public void setUp() throws Exception {
-    this.restoreDir = TEST_UTIL.getDataTestDir();
-
+    this.restoreDir = TEST_UTIL.getRandomDir();
   }
 
   @Override