Implement basic USB device enumeration on Android.

device/usb/usb_device_impl.cc

Index: device/usb/usb_device_impl.cc
diff --git a/device/usb/usb_device_impl.cc b/device/usb/usb_device_impl.cc
index ab9bd4aeacd8b8f053aaf675aebfffaf491fb732..8cf8c7f0ca4e26b2980edf8c04061082900557b8 100644
--- a/device/usb/usb_device_impl.cc
+++ b/device/usb/usb_device_impl.cc
@@ -201,7 +201,7 @@ void UsbDeviceImpl::Open(const OpenCallback& callback) {
 #endif  // defined(OS_CHROMEOS)
 }
 
-bool UsbDeviceImpl::Close(scoped_refptr<UsbDeviceHandle> handle) {
+void UsbDeviceImpl::Close(scoped_refptr<UsbDeviceHandle> handle) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   for (HandlesVector::iterator it = handles_.begin(); it != handles_.end();
@@ -209,10 +209,9 @@ bool UsbDeviceImpl::Close(scoped_refptr<UsbDeviceHandle> handle) {
     if (it->get() == handle.get()) {
       (*it)->InternalClose();
       handles_.erase(it);
-      return true;
+      return;
     }
   }
-  return false;
 }
 
 const UsbConfigDescriptor* UsbDeviceImpl::GetActiveConfiguration() {