Add equals() and hashCode() to Account class

Change-Id: I382537f1fc18e68d2c2f1542d12cebd08b1a8ac0
diff --git a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Account.java b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Account.java
index 94b37e1..221ba46 100644
--- a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Account.java
+++ b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Account.java
@@ -228,4 +228,14 @@
   public void setUserName(final String userName) {
     this.userName = userName;
   }
+
+  @Override
+  public boolean equals(Object o) {
+    return o instanceof Account && ((Account) o).getId().equals(getId());
+  }
+
+  @Override
+  public int hashCode() {
+    return getId().get();
+  }
 }