Mojo C++ bindings: remove some usage of AssociatedGroup from user code.

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

Index: mojo/public/cpp/bindings/tests/sync_method_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/sync_method_unittest.cc b/mojo/public/cpp/bindings/tests/sync_method_unittest.cc
index acd379a0cfc2824d6a430220f3bdbec9b1606192..b9c9890b6b71f1b95464f7a3da8e47444d56bb4e 100644
--- a/mojo/public/cpp/bindings/tests/sync_method_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/sync_method_unittest.cc
@@ -269,11 +269,8 @@ class SyncMethodAssociatedTest : public SyncMethodTest {
   void SetUp() override {
     master_impl_.reset(new TestSyncMasterImpl(MakeRequest(&master_ptr_)));
 
-    master_ptr_.associated_group()->CreateAssociatedInterface(
-        AssociatedGroup::WILL_PASS_REQUEST, &asso_ptr_info_, &asso_request_);
-    master_ptr_.associated_group()->CreateAssociatedInterface(
-        AssociatedGroup::WILL_PASS_PTR, &opposite_asso_ptr_info_,
-        &opposite_asso_request_);
+    asso_request_ = MakeRequest(&asso_ptr_info_);
+    opposite_asso_request_ = MakeRequest(&opposite_asso_ptr_info_);
 
     master_impl_->set_send_interface_handler(
         [this](TestSyncAssociatedPtrInfo ptr) {