CommentsInNotesUtil: Make a singleton

Change-Id: I3ebdc209dea8260f976f8e6e68c8da16be1d8a86
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/CommentsInNotesUtil.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/CommentsInNotesUtil.java
index e9b0905..99f9542 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/CommentsInNotesUtil.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/CommentsInNotesUtil.java
@@ -20,7 +20,6 @@
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
 
-import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Multimap;
 import com.google.common.primitives.Ints;
@@ -38,6 +37,7 @@
 import com.google.gerrit.server.config.AnonymousCowardName;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.ObjectId;
@@ -72,6 +72,7 @@
  * Utility functions to parse PatchLineComments out of a note byte array and
  * store a list of PatchLineComments in the form of a note (in a byte array).
  **/
+@Singleton
 public class CommentsInNotesUtil {
   private static final String AUTHOR = "Author";
   private static final String BASE_PATCH_SET = "Base-for-patch-set";
@@ -418,7 +419,6 @@
   private final PersonIdent serverIdent;
   private final String anonymousCowardName;
 
-  @VisibleForTesting
   @Inject
   public CommentsInNotesUtil(AccountCache accountCache,
       @GerritPersonIdent PersonIdent serverIdent,