Store devices that only need to be enumerated once

device/usb/usb_service_impl.h

 // Copyright 2015 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/usb/usb_service.h"
 
 #include <stddef.h>
 
 #include <map>
 #include <queue>
@@ skipping 62 matching lines @@
 
   // Handle hotplug events from libusb.
   static int LIBUSB_CALL HotplugCallback(libusb_context* context,
                                          PlatformUsbDevice device,
                                          libusb_hotplug_event event,
                                          void* user_data);
   // These functions release a reference to the provided platform device.
   void OnPlatformDeviceAdded(PlatformUsbDevice platform_device);
   void OnPlatformDeviceRemoved(PlatformUsbDevice platform_device);
 
+  // Add |platform_device| to the |ignored_devices_| and
+  // run |refresh_complete|.
+  void EnumerationFailed(PlatformUsbDevice platform_device,
+                         const base::Closure& refresh_complete);
+
   scoped_refptr<UsbContext> context_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
 
   // When available the device list will be updated when new devices are
   // connected instead of only when a full enumeration is requested.
   // TODO(reillyg): Support this on all platforms. crbug.com/411715
   bool hotplug_enabled_ = false;
   libusb_hotplug_callback_handle hotplug_handle_;
 
   // Enumeration callbacks are queued until an enumeration completes.
   bool enumeration_ready_ = false;
   bool enumeration_in_progress_ = false;
   std::queue<std::string> pending_path_enumerations_;
   std::vector<GetDevicesCallback> pending_enumeration_callbacks_;
 
   // The map from unique IDs to UsbDevices.
   typedef std::map<std::string, scoped_refptr<UsbDeviceImpl>> DeviceMap;
   DeviceMap devices_;
 
   // The map from PlatformUsbDevices to UsbDevices.
   typedef std::map<PlatformUsbDevice, scoped_refptr<UsbDeviceImpl>>
       PlatformDeviceMap;
   PlatformDeviceMap platform_devices_;
 
+  // The set of devices that only need to be enumerated once and then can be
+  // ignored (for example, hub devices, devices that failed enumeration, etc.).
+  std::set<PlatformUsbDevice> ignored_devices_;
+
   // Tracks PlatformUsbDevices that might be removed while they are being
   // enumerated.
   std::set<PlatformUsbDevice> devices_being_enumerated_;
 
 #if defined(OS_WIN)
   ScopedObserver<DeviceMonitorWin, DeviceMonitorWin::Observer> device_observer_;
 #endif  // OS_WIN
 
   base::WeakPtrFactory<UsbServiceImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbServiceImpl);
 };
 
 }  // namespace device