Relanding "Multiprocess test client: Android child process launcher rework."

base/test/android/java/src/org/chromium/base/MultiprocessTestClientService2.java

Index: base/test/android/java/src/org/chromium/base/MultiprocessTestClientService2.java
diff --git a/base/test/android/java/src/org/chromium/base/MultiprocessTestClientService2.java b/base/test/android/java/src/org/chromium/base/MultiprocessTestClientService2.java
new file mode 100644
index 0000000000000000000000000000000000000000..aad11f1c23e9afb5fa779c903971579791a5ada1
--- /dev/null
+++ b/base/test/android/java/src/org/chromium/base/MultiprocessTestClientService2.java
@@ -0,0 +1,10 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.base;
+
+/**
+ * A subclass used only to differentiate different test client service process instances.
+ */
+public class MultiprocessTestClientService2 extends MultiprocessTestClientService {}