More reliably get futures returned by ChangeIndexer

Convert futures to be CheckedFuture<?, IOException>s so calling
checkedGet() does not result in too many extra exception types. Rename
the methods to {index,delete}Async so it is clear that these just
launch a future. For all usages, make sure checkedGet() is invoked on
the future, either immediately or after another block of non-Change-
mutating code.

Change-Id: I18b55b0b03b2be0a70995a0b08a4fc3193db96e3

gerrit-server/src/main/java/com/google/gerrit/server/change/PostReviewers.java

@@ -20,6 +20,7 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
+import com.google.common.util.concurrent.CheckedFuture;
 import com.google.gerrit.common.ChangeHooks;
 import com.google.gerrit.common.data.GroupDescription;
 import com.google.gerrit.common.errors.EmailException;
@@ -151,7 +152,7 @@ public class PostReviewers implements RestModifyView<ChangeResource, Input> {
   }
 
   private PostResult putAccount(ReviewerResource rsrc) throws OrmException,
-      EmailException {
+      EmailException, IOException {
     PostResult result = new PostResult();
     addReviewers(rsrc, result, ImmutableSet.of(rsrc.getUser()));
     return result;
@@ -219,7 +220,8 @@ public class PostReviewers implements RestModifyView<ChangeResource, Input> {
   }
 
   private void addReviewers(ChangeResource rsrc, PostResult result,
-      Set<IdentifiedUser> reviewers) throws OrmException, EmailException {
+      Set<IdentifiedUser> reviewers)
+      throws OrmException, EmailException, IOException {
     if (reviewers.isEmpty()) {
       result.reviewers = ImmutableList.of();
       return;
@@ -259,9 +261,10 @@ public class PostReviewers implements RestModifyView<ChangeResource, Input> {
       db.rollback();
     }
 
-    indexer.index(rsrc.getChange());
+    CheckedFuture<?, IOException> indexFuture = indexer.indexAsync(rsrc.getChange());
     accountLoaderFactory.create(true).fill(result.reviewers);
     postAdd(rsrc.getChange(), result);
+    indexFuture.checkedGet();
   }
 
   private void postAdd(Change change, PostResult result)