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

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

 // Copyright 2015 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.
 
 #include <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 95 matching lines @@
     ScopedInterfaceEndpointHandle handle = ptr_info.PassHandle();
     CHECK(!handle.is_local());
     return AssociatedInterfacePtrInfo<T>(
         target->CreateLocalEndpointHandle(handle.release()),
         ptr_info.version());
   }
 
   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());
   }
 
   void CreateIntegerSenderWithExistingRouters(
       scoped_refptr<MultiplexRouter> router0,
       IntegerSenderAssociatedPtrInfo* ptr_info0,
       scoped_refptr<MultiplexRouter> router1,
       IntegerSenderAssociatedRequest* request1) {
     router1->CreateAssociatedGroup()->CreateAssociatedInterface(
         AssociatedGroup::WILL_PASS_PTR, ptr_info0, request1);
@@ skipping 858 matching lines @@
       run_loop.QuitClosure()));
 
   request.ResetWithReason(789u, "long time no see");
 
   run_loop.Run();
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo