media/midi: Fix warnings found by clang chromium-style plugin on Windows.

media/midi/midi_manager_win.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 "media/midi/midi_manager_win.h"
 
 #include <windows.h>
 #include <ks.h>
 #include <ksmedia.h>
 #include <mmreg.h>
@@ skipping 1075 matching lines @@
   // This flag can be used as the signal that when background tasks must be
   // interrupted.
   // TODO(toyoshim): Use std::atomic<bool> when it is allowed.
   volatile bool destructor_started;
 
   DISALLOW_COPY_AND_ASSIGN(MidiServiceWinImpl);
 };
 
 }  // namespace
 
+MidiManagerWin::MidiManagerWin() {
+}
+
+MidiManagerWin::~MidiManagerWin() {
+  midi_service_.reset();

[Nico, 2015/04/29 03:21:49]

Is the explicit reset() call needed at all? There's only a single member, so
omitting this line shouldn't make a difference I think.

+}
+
 void MidiManagerWin::StartInitialization() {
   midi_service_.reset(new MidiServiceWinImpl);
   // Note that |CompleteInitialization()| will be called from the callback.
   midi_service_->InitializeAsync(this);
 }
 
 void MidiManagerWin::DispatchSendMidiData(MidiManagerClient* client,
                                           uint32 port_index,
                                           const std::vector<uint8>& data,
                                           double timestamp) {
@@ skipping 11 matching lines @@
   // TOOD(toyoshim): This calculation should be done when the date is actually
   // sent.
   client->AccumulateMidiBytesSent(data.size());
 }
 
 MidiManager* MidiManager::Create() {
   return new MidiManagerWin();
 }
 
 }  // namespace media