Remove the MessageLoop::DestructionObserver from mojo bindings.

device/bluetooth/device_unittest.cc

 // Copyright 2016 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 "device/bluetooth/device.h"
 
 #include <memory>
 #include <string>
 #include <utility>
 
@@ skipping 123 matching lines @@
 
     proxy_.set_connection_error_handler(
         base::Bind(&BluetoothInterfaceDeviceTest::OnConnectionError,
                    weak_factory_.GetWeakPtr()));
   }
 
   void TearDown() override {
     EXPECT_EQ(expected_success_callback_calls_, actual_success_callback_calls_);
     EXPECT_EQ(message_pipe_closed_, expect_device_service_deleted_);
     proxy_.reset();
+    base::RunLoop().RunUntilIdle();
   }
 
  protected:
   void OnConnectionError() { message_pipe_closed_ = true; }
 
   void SimulateGattServicesDiscovered() {
     for (auto& observer : adapter_->GetObservers())
       observer.GattServicesDiscovered(adapter_.get(), &device_);
   }
 
@@ skipping 112 matching lines @@
   EXPECT_EQ(0, actual_callback_count_);
 
   // Simulate connection loss.
   proxy_->Disconnect();
   expect_device_service_deleted_ = true;
 
   // Wait for message pipe to process error.
   base::RunLoop().RunUntilIdle();
 }
 }  // namespace bluetooth