Add browser tests for USB device add/remove events.

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 <map>
+
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "device/usb/usb_context.h"
+#include "device/usb/usb_device_impl.h"
+#include "third_party/libusb/src/libusb/libusb.h"
+
+namespace device {
+
+typedef struct libusb_device* PlatformUsbDevice;
+typedef struct libusb_context* PlatformUsbContext;
+
+class UsbServiceImpl : public UsbService {
+ public:
+  static UsbService* Create(
+      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
+
+ private:
+  explicit UsbServiceImpl(
+      PlatformUsbContext context,
+      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
+  ~UsbServiceImpl() override;
+
+  // device::UsbService implementation
+  scoped_refptr<UsbDevice> GetDeviceById(uint32 unique_id) override;
+  void GetDevices(std::vector<scoped_refptr<UsbDevice>>* devices) override;
+
+  // Enumerate USB devices from OS and update devices_ map.
+  void RefreshDevices();
+
+  // Adds a new UsbDevice to the devices_ map based on the given libusb device.
+  scoped_refptr<UsbDeviceImpl> AddDevice(PlatformUsbDevice platform_device);
+
+  // 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 OnDeviceAdded(PlatformUsbDevice platform_device);
+  void OnDeviceRemoved(PlatformUsbDevice platform_device);
+
+  scoped_refptr<UsbContext> context_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
+
+#if defined(OS_WIN)
+  class UIThreadHelper;
+  UIThreadHelper* ui_thread_helper_;
+#endif  // OS_WIN
+
+  // TODO(reillyg): Figure out a better solution for device IDs.
+  uint32 next_unique_id_;
+
+  // 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_;
+  libusb_hotplug_callback_handle hotplug_handle_;
+
+  // The map from unique IDs to UsbDevices.
+  typedef std::map<uint32, scoped_refptr<UsbDeviceImpl>> DeviceMap;
+  DeviceMap devices_;
+
+  // The map from PlatformUsbDevices to UsbDevices.
+  typedef std::map<PlatformUsbDevice, scoped_refptr<UsbDeviceImpl>>
+      PlatformDeviceMap;
+  PlatformDeviceMap platform_devices_;
+
+  base::WeakPtrFactory<UsbServiceImpl> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(UsbServiceImpl);
+};
+
+}  // namespace device