Shuwdown executors after executing all tasks.

Bug: 14113276
Change-Id: Ie42ef30ffe5767ca434db4669efad2027b474e74

java/src/com/android/inputmethod/latin/utils/ExecutorUtils.java

@@ -47,9 +47,14 @@ public class ExecutorUtils {
     public static void shutdownAllExecutors() {
         synchronized(sExecutorMap) {
             for (final PrioritizedSerialExecutor executor : sExecutorMap.values()) {
+                executor.execute(new Runnable() {
+                    @Override
+                    public void run() {
                         executor.shutdown();
                         sExecutorMap.remove(executor);
                     }
+                });
+            }
         }
     }
 }