Allow Skyframe tests to use the NotifyingGraph and DeterministicGraph helpers to enforce concurrency synchronization points and determinism even if they are not using an InMemoryGraph-backed evaluator.

--
MOS_MIGRATED_REVID=121977783
diff --git a/src/test/java/com/google/devtools/build/skyframe/InMemoryGraphConcurrencyTest.java b/src/test/java/com/google/devtools/build/skyframe/InMemoryGraphConcurrencyTest.java
index 28f0da3..18d6875 100644
--- a/src/test/java/com/google/devtools/build/skyframe/InMemoryGraphConcurrencyTest.java
+++ b/src/test/java/com/google/devtools/build/skyframe/InMemoryGraphConcurrencyTest.java
@@ -18,7 +18,7 @@
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
-/** Concurrency tests for {@link InMemoryGraph}. */
+/** Concurrency tests for {@link InMemoryGraphImpl}. */
 @RunWith(JUnit4.class)
 public class InMemoryGraphConcurrencyTest extends GraphConcurrencyTest {
   private ProcessableGraph graph;
@@ -36,7 +36,7 @@
 
   @Override
   protected void makeGraph() {
-    graph = new InMemoryGraph();
+    graph = new InMemoryGraphImpl();
   }
 
   @Override