[Mojo] Change the misleading comment for AutoCloseableRouter.

AutoCloseableRouter implements close() method from java.io.Closeable,
however close() will be called only when used with try-with-resources
statement. Normally this class won't be in a try-with-resources
statement unfortunately, so one needs to call close() explicitly.

Bug: None
Test: No logic change, only comments.
Change-Id: I9c0b36372b8b51f0d3610fb82799db42a1fb910d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2081012Reviewed-by: Ken Rockot <rockot@google.com>
Commit-Queue: Shimi Zhang <ctzsm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746109}

mojo/public/java/bindings/src/org/chromium/mojo/bindings/AutoCloseableRouter.java

@@ -10,7 +10,9 @@ import org.chromium.mojo.system.MessagePipeHandle;
 import java.util.concurrent.Executor;
 
 /**
- * Wrapper around {@link Router} that will close the connection when not referenced anymore.
+ * Wrapper around {@link Router}. Unlike the class name suggested, it doesn't auto-close the
+ * connection without a try-with-resources statement. If the callsite isn't using try-with-resources
+ * mechanism, it needs to call close() explicitly.
  */
 class AutoCloseableRouter implements Router {
     /**