Implement basic USB device enumeration on Android.

device/usb/usb_device.h

Index: device/usb/usb_device.h
diff --git a/device/usb/usb_device.h b/device/usb/usb_device.h
index beb78036e57d92f9df47939df0ca58de760cc580..a6fc6e5f7fe1ef80bf15a7d766dd9740a3c7ee9f 100644
--- a/device/usb/usb_device.h
+++ b/device/usb/usb_device.h
@@ -5,6 +5,7 @@
 #ifndef DEVICE_USB_USB_DEVICE_H_
 #define DEVICE_USB_USB_DEVICE_H_
 
+#include <string>
 #include <vector>
 
 #include "base/callback.h"
@@ -56,10 +57,6 @@ class UsbDevice : public base::RefCountedThreadSafe<UsbDevice> {
   // Creates a UsbDeviceHandle for further manipulation.
   virtual void Open(const OpenCallback& callback) = 0;
 
-  // Explicitly closes a device handle. This method will be automatically called
-  // by the destructor of a UsbDeviceHandle as well.
-  virtual bool Close(scoped_refptr<UsbDeviceHandle> handle) = 0;
-
   // Gets the UsbConfigDescriptor for the active device configuration or nullptr
   // if the device is unconfigured.
   virtual const UsbConfigDescriptor* GetActiveConfiguration() = 0;