Implement support for USB Xbox360 controllers without a driver on Mac.

content/browser/gamepad/gamepad_provider.cc

 // Copyright (c) 2012 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 <cmath>
 #include <set>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 95 matching lines @@
   size_t data_size = sizeof(GamepadHardwareBuffer);
   base::SystemMonitor* monitor = base::SystemMonitor::Get();
   if (monitor)
     monitor->AddDevicesChangedObserver(this);
   bool res = gamepad_shared_memory_.CreateAndMapAnonymous(data_size);
   CHECK(res);
   GamepadHardwareBuffer* hwbuf = SharedMemoryAsHardwareBuffer();
   memset(hwbuf, 0, sizeof(GamepadHardwareBuffer));
 
   polling_thread_.reset(new base::Thread("Gamepad polling thread"));
-  polling_thread_->StartWithOptions(
-      base::Thread::Options(base::MessageLoop::TYPE_IO, 0));
+#if defined(OS_MACOSX)
+  // On Mac, the data fetcher uses IOKit which depends on CFRunLoop, so the
+  // message loop needs to be a UI-type loop.
+  const base::MessageLoop::Type kMessageLoopType = base::MessageLoop::TYPE_UI;
+#else
+  // On Linux, the data fetcher needs to watch file descriptors, so the message
+  // loop needs to be a libevent loop. On Windows it doesn't matter what the
+  // loop is.
+  const base::MessageLoop::Type kMessageLoopType = base::MessageLoop::TYPE_IO;
+#endif
+  polling_thread_->StartWithOptions(base::Thread::Options(kMessageLoopType, 0));
 
   polling_thread_->message_loop()->PostTask(
       FROM_HERE,
       base::Bind(&GamepadProvider::DoInitializePollingThread,
                  base::Unretained(this),
                  base::Passed(&fetcher)));
 }
 
 void GamepadProvider::DoInitializePollingThread(
     scoped_ptr<GamepadDataFetcher> fetcher) {
@@ skipping 74 matching lines @@
   if (GamepadsHaveUserGesture(SharedMemoryAsHardwareBuffer()->buffer)) {
     for (size_t i = 0; i < user_gesture_observers_.size(); i++) {
       user_gesture_observers_[i].message_loop->PostTask(FROM_HERE,
           user_gesture_observers_[i].closure);
     }
     user_gesture_observers_.clear();
   }
 }
 
 }  // namespace content