Change mojo enums to be scoped enums in the generated C++ bindings.

device/devices_app/usb/public/interfaces/device.mojom

 // 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.
 
 module device.usb;
 
 enum OpenDeviceError {
   // Opening the device succeeded.
   OK,
 
   // The operating system denied access to the device.
   ACCESS_DENIED,
 };
 
 enum TransferDirection {
-  IN,
-  OUT,
+  INBOUND,
+  OUTBOUND,
 };
 
 enum ControlTransferType {
   STANDARD,
   CLASS,
   VENDOR,
   RESERVED
 };
 
 enum ControlTransferRecipient {
@@ skipping 78 matching lines @@
   uint8 request;
   uint16 value;
   uint16 index;
 };
 
 enum TransferStatus {
   // The transfer completed successfully.
   COMPLETED,
 
   // The transfer failed due to a non-specific error.
-  ERROR,
+  TRANSFER_ERROR,
 
   // The transfer was not allowed.
   PERMISSION_DENIED,
 
   // The transfer timed out.
   TIMEOUT,
 
   // The transfer was cancelled.
   CANCELLED,
 
@@ skipping 138 matching lines @@
   // this transfer.
   //
   // |timeout| specifies the request timeout in milliseconds. A timeout of 0
   // indicates no timeout: the request will remain pending indefinitely until
   // completed or otherwise terminated.
   IsochronousTransferOut(uint8 endpoint_number,
                          array<array<uint8>> packets,
                          uint32 timeout)
       => (TransferStatus status);
 };