Fix ThreadSafeAssociatedInterfacePtrProvider raciness.

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

 // Copyright 2013 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 <stdint.h>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
@@ skipping 836 matching lines @@
       },
       base::SequencedTaskRunnerHandle::Get(), run_loop.QuitClosure(),
       thread_safe_ptr);
   other_thread.message_loop()->task_runner()->PostTask(FROM_HERE, run_method);
 
   // Block until the method callback is called on the background thread.
   run_loop.Run();
 }
 
 TEST_F(InterfacePtrTest, BindLaterThreadSafeInterfacePointer) {
-  // Create a ThreadSafeInterfacePtr that we'll bind from a different thread.
-  scoped_refptr<math::ThreadSafeCalculatorPtr> thread_safe_ptr =
-      math::ThreadSafeCalculatorPtr::CreateUnbound();
-  ASSERT_TRUE(thread_safe_ptr);
-
   // Create and start the thread from where we'll bind the interface pointer.
   base::Thread other_thread("service test thread");
   other_thread.Start();
   const scoped_refptr<base::SingleThreadTaskRunner>& other_thread_task_runner =
       other_thread.message_loop()->task_runner();
+
+  // Create a ThreadSafeInterfacePtr that we'll bind from a different thread.
+  scoped_refptr<math::ThreadSafeCalculatorPtr> thread_safe_ptr =
+      math::ThreadSafeCalculatorPtr::CreateUnbound(other_thread_task_runner);
+  ASSERT_TRUE(thread_safe_ptr);
+
   MathCalculatorImpl* math_calc_impl = nullptr;
   {
     base::RunLoop run_loop;
     auto run_method = base::Bind(
         [](const scoped_refptr<base::TaskRunner>& main_task_runner,
            const base::Closure& quit_closure,
            const scoped_refptr<math::ThreadSafeCalculatorPtr>& thread_safe_ptr,
            MathCalculatorImpl** math_calc_impl) {
           math::CalculatorPtr ptr;
           // In real life, the implementation would have a legitimate owner.
@@ skipping 24 matching lines @@
   other_thread_task_runner->DeleteSoon(FROM_HERE, math_calc_impl);
 
   // Reset the pointer now so the InterfacePtr associated resources can be
   // deleted before the background thread's message loop is invalidated.
   thread_safe_ptr = nullptr;
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo