[TEST] Mock Directory didn't clean wrapped dirs

I ran the bad apple test for index memory leaks and still saw leaks, it seems like we don't properly clean the dirs from the static mock test dir wrapper

src/test/java/org/elasticsearch/indices/leaks/IndicesLeaksTests.java

@@ -54,7 +54,7 @@ public class IndicesLeaksTests extends ElasticsearchIntegrationTest {
 
         client().admin().cluster().prepareHealth().setWaitForGreenStatus().execute().actionGet();
 
-        IndicesService indicesService = internalCluster().getInstance(IndicesService.class);
+        IndicesService indicesService = internalCluster().getDataNodeInstance(IndicesService.class);
         IndexService indexService = indicesService.indexServiceSafe("test");
         Injector indexInjector = indexService.injector();
         IndexShard shard = indexService.shardSafe(0);
@@ -90,7 +90,7 @@ public class IndicesLeaksTests extends ElasticsearchIntegrationTest {
         shard = null;
         shardInjector = null;
 
-        client().admin().indices().prepareDelete().execute().actionGet();
+        cluster().wipeIndices("test");
 
         for (int i = 0; i < 100; i++) {
             System.gc();
@@ -112,7 +112,7 @@ public class IndicesLeaksTests extends ElasticsearchIntegrationTest {
             }
         }
 
-        //Thread.sleep(1000000);
+        //System.out.println("sleeping");Thread.sleep(1000000);
 
         for (WeakReference indexReference : indexReferences) {
             assertThat("dangling index reference: " + indexReference.get(), indexReference.get(), nullValue());

src/test/java/org/elasticsearch/test/store/MockDirectoryHelper.java

@@ -141,6 +141,7 @@ public class MockDirectoryHelper {
                 synchronized (lock) {
                     lock.notifyAll();
                 }
+                wrappers.remove(this);
             }
         }