Remove deprecated changeMerge thread pool size configurations

changeMerge.threadPoolSize and changeMerge.interactiveThreadPoolSize are
deprecated since 2.11, it's time to remove them.

Change-Id: I1c799954b9afabff7dac3da10f53bb7e9bdde916
diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt
index 3237a8c..fc08cdc 100644
--- a/Documentation/config-gerrit.txt
+++ b/Documentation/config-gerrit.txt
@@ -1107,25 +1107,6 @@
 +
 Default is 300 seconds (5 minutes).
 
-[[changeMerge.threadPoolSize]]changeMerge.threadPoolSize::
-+
-_Deprecated:_ Formerly used to control thread pool size for background
-mergeability checks. These checks were moved to the indexing threadpool,
-so this value is now used for
-link:#index.batchThreads[index.batchThreads], only if that value is not
-provided.
-+
-This option may be removed in a future version.
-
-[[changeMerge.interactiveThreadPoolSize]]changeMerge.interactiveThreadPoolSize::
-+
-_Deprecated:_ Formerly used to control thread pool size for interactive
-mergeability checks. These checks were moved to the indexing threadpool,
-so this value is now used for link:#index.threads[index.threads], only
-if that value is not provided.
-+
-This option may be removed in a future version.
-
 [[commentlink]]
 === Section commentlink
 
@@ -2421,9 +2402,7 @@
 +
 Number of threads to use for indexing in normal interactive operations.
 +
-Defaults to 1 if not set, or set to a negative value (unless
-link:#changeMerge.interactiveThreadPoolSize[changeMerge.interactiveThreadPoolSize]
-is iset).
+Defaults to 1 if not set, or set to a negative value.
 
 [[index.batchThreads]]index.batchThreads::
 +
@@ -2431,8 +2410,7 @@
 online schema upgrades.
 +
 If not set or set to a negative value, defaults to the number of logical
-CPUs as returned by the JVM (unless
-link:#changeMerge.threadPoolSize[changeMerge.threadPoolSize] is set).
+CPUs as returned by the JVM.
 
 [[index.onlineUpgrade]]index.onlineUpgrade::
 +
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/index/IndexModule.java b/gerrit-server/src/main/java/com/google/gerrit/server/index/IndexModule.java
index fe06c41..befd5ed 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/index/IndexModule.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/index/IndexModule.java
@@ -140,10 +140,6 @@
       threads = config.getInt("index", null, "threads", 0);
     }
     if (threads <= 0) {
-      threads =
-          config.getInt("changeMerge", null, "interactiveThreadPoolSize", 0);
-    }
-    if (threads <= 0) {
       return MoreExecutors.newDirectExecutorService();
     }
     return MoreExecutors.listeningDecorator(
@@ -161,9 +157,6 @@
     }
     int threads = config.getInt("index", null, "batchThreads", 0);
     if (threads <= 0) {
-      threads = config.getInt("changeMerge", null, "threadPoolSize", 0);
-    }
-    if (threads <= 0) {
       threads = Runtime.getRuntime().availableProcessors();
     }
     return MoreExecutors.listeningDecorator(