Implement basic USB device enumeration on Android.

device/usb/usb_device_impl.h

 // 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.
 
 #ifndef DEVICE_USB_USB_DEVICE_IMPL_H_
 #define DEVICE_USB_USB_DEVICE_IMPL_H_
 
+#include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/threading/thread_checker.h"
 #include "device/usb/usb_descriptors.h"
 #include "device/usb/usb_device.h"
 #include "device/usb/webusb_descriptors.h"
 
 struct libusb_device;
 struct libusb_config_descriptor;
@@ skipping 16 matching lines @@
 typedef struct libusb_config_descriptor* PlatformUsbConfigDescriptor;
 typedef struct libusb_device_handle* PlatformUsbDeviceHandle;
 
 class UsbDeviceImpl : public UsbDevice {
  public:
 // UsbDevice implementation:
 #if defined(OS_CHROMEOS)
   void CheckUsbAccess(const ResultCallback& callback) override;
 #endif  // OS_CHROMEOS
   void Open(const OpenCallback& callback) override;
-  bool Close(scoped_refptr<UsbDeviceHandle> handle) override;
   const UsbConfigDescriptor* GetActiveConfiguration() override;
 
   // These functions are used during enumeration only. The values must not
   // change during the object's lifetime.
   void set_manufacturer_string(const base::string16& value) {
     manufacturer_string_ = value;
   }
   void set_product_string(const base::string16& value) {
     product_string_ = value;
   }
@@ skipping 21 matching lines @@
 
   ~UsbDeviceImpl() override;
 
   // Called only by UsbServiceImpl.
   void set_visited(bool visited) { visited_ = visited; }
   bool was_visited() const { return visited_; }
   void OnDisconnect();
   void ReadAllConfigurations();
 
   // Called by UsbDeviceHandleImpl.
+  void Close(scoped_refptr<UsbDeviceHandle> handle);
   void RefreshActiveConfiguration();
 
  private:
   void GetAllConfigurations();
 #if defined(OS_CHROMEOS)
   void OnOpenRequestComplete(const OpenCallback& callback,
                              dbus::FileDescriptor fd);
   void OpenOnBlockingThreadWithFd(dbus::FileDescriptor fd,
                                   const OpenCallback& callback);
 #endif
@@ skipping 23 matching lines @@
 
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbDeviceImpl);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_USB_USB_DEVICE_IMPL_H_