Mojo C++ bindings: remove the lock in MultiplexRouter if it only serves a single interface.

mojo/public/cpp/bindings/tests/associated_interface_unittest.cc

Index: mojo/public/cpp/bindings/tests/associated_interface_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/associated_interface_unittest.cc b/mojo/public/cpp/bindings/tests/associated_interface_unittest.cc
index baf53966d37568e13d2da28ee91529224d757c48..8c91c3cd695d6f0d2a0e4a18e5ed4491298b9e19 100644
--- a/mojo/public/cpp/bindings/tests/associated_interface_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/associated_interface_unittest.cc
@@ -113,9 +113,11 @@ class AssociatedInterfaceTest : public testing::Test {
   void CreateRouterPair(scoped_refptr<MultiplexRouter>* router0,
                         scoped_refptr<MultiplexRouter>* router1) {
     MessagePipe pipe;
-    *router0 = new MultiplexRouter(true, std::move(pipe.handle0),
+    *router0 = new MultiplexRouter(std::move(pipe.handle0),
+                                   MultiplexRouter::MULTI_INTERFACE, true,
                                    base::ThreadTaskRunnerHandle::Get());
-    *router1 = new MultiplexRouter(false, std::move(pipe.handle1),
+    *router1 = new MultiplexRouter(std::move(pipe.handle1),
+                                   MultiplexRouter::MULTI_INTERFACE, false,
                                    base::ThreadTaskRunnerHandle::Get());
   }