Web MIDI: introduce MidiManager::Shutdown to shutdown gracefully

media/midi/midi_manager_usb_unittest.cc

 // Copyright 2014 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 "media/midi/midi_manager_usb.h"
 
 #include <string>
 
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
@@ skipping 163 matching lines @@
 };
 
 class MidiManagerUsbTest : public ::testing::Test {
  public:
   MidiManagerUsbTest() : message_loop_(new base::MessageLoop) {
     scoped_ptr<TestUsbMidiDeviceFactory> factory(new TestUsbMidiDeviceFactory);
     factory_ = factory.get();
     manager_.reset(new MidiManagerUsbForTesting(factory.Pass()));
   }
   ~MidiManagerUsbTest() override {
+    manager_->Shutdown();
+    base::RunLoop run_loop;
+    run_loop.RunUntilIdle();
+
     std::string leftover_logs = logger_.TakeLog();
     if (!leftover_logs.empty()) {
       ADD_FAILURE() << "Log should be empty: " << leftover_logs;
     }
   }
 
  protected:
   void Initialize() {
     client_.reset(new FakeMidiManagerClient(&logger_));
     manager_->StartSession(client_.get());
@@ skipping 372 matching lines @@
   EXPECT_EQ(3u, manager_->output_streams()[1]->jack().jack_id);
   ASSERT_EQ(1u, jacks.size());
   EXPECT_EQ(2, jacks[0].endpoint_number());
   EXPECT_EQ("UsbMidiDevice::GetDescriptors\n", logger_.TakeLog());
 }
 
 }  // namespace
 
 }  // namespace midi
 }  // namespace media