Remove DownstreamCreatorIT#testDiamondMerge_identicalDiamondSides

This test froze the time to create 2 changes with the same commit SHA1.
Having 2 changes with the same commit SHA1 (on the same target branch)
is an inconsistency that Gerrit cannot deal well with. This is why
Gerrit was fixed so that changes which are created with the same
content, on the same base commit and at the same timestamp have
different SHA1s now. This is achieved by generating random Change-Ids,
instead of computing them (see change Ie4f01e5a3). Since the Change-Id
is part of the commit message, each change has a different SHA1 now.
Since the test tested a situation with inconsitent data in Gerrit which
can no longer occur, the test should be dropped.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: If10a1ca63f4dc54537dca692132ed9ccfef21f83
diff --git a/src/test/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreatorIT.java b/src/test/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreatorIT.java
index af7099f..8a6c7c9 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreatorIT.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreatorIT.java
@@ -39,18 +39,15 @@
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.server.group.SystemGroupBackend;
-import com.google.gerrit.testing.TestTimeUtil;
 import com.google.inject.Inject;
 import com.googlesource.gerrit.plugins.automerger.helpers.ConfigOption;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.EnumSet;
 import java.util.List;
-import java.util.concurrent.TimeUnit;
 import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
 import org.eclipse.jgit.junit.TestRepository;
 import org.eclipse.jgit.lib.Config;
@@ -226,83 +223,6 @@
   }
 
   @Test
-  public void testDiamondMerge_identicalDiamondSides() throws Exception {
-    Project.NameKey manifestNameKey = defaultSetup();
-    // Create initial change
-    PushOneCommit.Result initialResult = createChange("subject", "filename", "echo Hello");
-    // Project name is scoped by test, so we need to get it from our initial change
-    String projectName = initialResult.getChange().project().get();
-    createBranch(new Branch.NameKey(projectName, "left"));
-    createBranch(new Branch.NameKey(projectName, "right"));
-    initialResult.assertOkStatus();
-    merge(initialResult);
-
-    String leftRevision = gApi.projects().name(projectName).branch("left").get().revision;
-    String rightRevision = gApi.projects().name(projectName).branch("right").get().revision;
-    // For this test, right == left
-    assertThat(leftRevision).isEqualTo(rightRevision);
-    createBranch(new Branch.NameKey(projectName, "bottom"));
-    pushDiamondConfig(manifestNameKey.get(), projectName);
-
-    // Freeze time so that the merge commit from left->bottom and right->bottom have same SHA
-    TestTimeUtil.resetWithClockStep(0, TimeUnit.MILLISECONDS);
-    TestTimeUtil.setClock(new Timestamp(TestTimeUtil.START.toEpochMilli()));
-    // After we upload our config, we upload a new patchset to create the downstreams.
-    PushOneCommit.Result result =
-        createChange(testRepo, "master", "subject", "filename2", "echo Hello", "sometopic");
-    TestTimeUtil.useSystemTime();
-    result.assertOkStatus();
-
-    List<ChangeInfo> changesInTopic =
-        gApi.changes()
-            .query("topic: " + gApi.changes().id(result.getChangeId()).topic())
-            .withOption(ListChangesOption.CURRENT_REVISION)
-            .get();
-    assertThat(changesInTopic).hasSize(4);
-    // +2 and submit
-    merge(result);
-    List<ChangeInfo> sortedChanges = sortedChanges(changesInTopic);
-
-    // Should create two changes on bottom, since left and right are different.
-    ChangeInfo bottomChangeInfo = sortedChanges.get(0);
-    assertThat(bottomChangeInfo.branch).isEqualTo("bottom");
-    ChangeApi bottomChange = gApi.changes().id(bottomChangeInfo._number);
-    assertThat(getVote(bottomChange, "Code-Review").value).isEqualTo(2);
-    assertThat(getVote(bottomChange, "Code-Review").tag).isEqualTo("autogenerated:Automerger");
-
-    ChangeInfo leftChangeInfo = sortedChanges.get(1);
-    assertThat(leftChangeInfo.branch).isEqualTo("left");
-    ChangeApi leftChange = gApi.changes().id(leftChangeInfo._number);
-    assertThat(getVote(leftChange, "Code-Review").value).isEqualTo(2);
-    assertThat(getVote(leftChange, "Code-Review").tag).isEqualTo("autogenerated:Automerger");
-
-    ChangeInfo masterChangeInfo = sortedChanges.get(2);
-    assertThat(masterChangeInfo.branch).isEqualTo("master");
-    ChangeApi masterChange = gApi.changes().id(masterChangeInfo._number);
-    assertThat(getVote(masterChange, "Code-Review").value).isEqualTo(2);
-    assertThat(getVote(masterChange, "Code-Review").tag).isEqualTo(null);
-
-    ChangeInfo rightChangeInfo = sortedChanges.get(3);
-    assertThat(rightChangeInfo.branch).isEqualTo("right");
-    ChangeApi rightChange = gApi.changes().id(rightChangeInfo._number);
-    assertThat(getVote(rightChange, "Code-Review").value).isEqualTo(2);
-    assertThat(getVote(rightChange, "Code-Review").tag).isEqualTo("autogenerated:Automerger");
-
-    // Ensure that commit subjects are correct
-    String masterSubject = masterChangeInfo.subject;
-    String shortMasterSha = masterChangeInfo.currentRevision.substring(0, 10);
-    String shortLeftSha = leftChangeInfo.currentRevision.substring(0, 10);
-    assertThat(masterChangeInfo.subject).doesNotContainMatch("automerger");
-    assertThat(leftChangeInfo.subject)
-        .isEqualTo("[automerger] " + masterSubject + " am: " + shortMasterSha);
-    assertThat(rightChangeInfo.subject)
-        .isEqualTo("[automerger] " + masterSubject + " am: " + shortMasterSha);
-    assertThat(bottomChangeInfo.subject)
-        .isEqualTo(
-            "[automerger] " + masterSubject + " am: " + shortMasterSha + " am: " + shortLeftSha);
-  }
-
-  @Test
   public void testChangeStack() throws Exception {
     Project.NameKey manifestNameKey = defaultSetup();
     // Create initial change