Mojo C++ bindings: Simplify associated interface API.

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

Index: mojo/public/cpp/bindings/tests/multiplex_router_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/multiplex_router_unittest.cc b/mojo/public/cpp/bindings/tests/multiplex_router_unittest.cc
index 0db42db25fc7e4f5a0c78ae02a8a4d31f9bc62a2..31963e0f5bbb44a87f6c636482b70bc992859989 100644
--- a/mojo/public/cpp/bindings/tests/multiplex_router_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/multiplex_router_unittest.cc
@@ -37,23 +37,16 @@ class MultiplexRouterTest : public testing::Test {
     router1_ = new MultiplexRouter(std::move(pipe.handle1),
                                    MultiplexRouter::MULTI_INTERFACE, true,
                                    base::ThreadTaskRunnerHandle::Get());
-    router0_->CreateEndpointHandlePair(&endpoint0_, &endpoint1_);
-    endpoint1_ =
-        EmulatePassingEndpointHandle(std::move(endpoint1_), router1_.get());
+    ScopedInterfaceEndpointHandle::CreatePairPendingAssociation(&endpoint0_,
+                                                                &endpoint1_);
+    auto id = router0_->AssociateInterface(std::move(endpoint1_));
+    endpoint1_ = router1_->CreateLocalEndpointHandle(id);
   }
 
   void TearDown() override {}
 
   void PumpMessages() { base::RunLoop().RunUntilIdle(); }
 
-  ScopedInterfaceEndpointHandle EmulatePassingEndpointHandle(
-      ScopedInterfaceEndpointHandle handle,
-      MultiplexRouter* target) {
-    CHECK(!handle.is_local());
-
-    return target->CreateLocalEndpointHandle(handle.release());
-  }
-
  protected:
   scoped_refptr<MultiplexRouter> router0_;
   scoped_refptr<MultiplexRouter> router1_;