Remove the code added to make extensions compile on Aura Android.

extensions/browser/api/serial/serial_api.cc

 // 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.
 
 #include "extensions/browser/api/serial/serial_api.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/values.h"
@@ skipping 68 matching lines @@
 }
 
 bool SerialGetDevicesFunction::Prepare() {
   set_work_thread_id(BrowserThread::FILE);
   return true;
 }
 
 void SerialGetDevicesFunction::Work() {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 
-// TODO(moshayedi): crbug.com/549257. Add USB support for Aura on Android.
-#if !defined(OS_ANDROID)
   scoped_ptr<device::SerialDeviceEnumerator> enumerator =
       device::SerialDeviceEnumerator::Create();
   mojo::Array<device::serial::DeviceInfoPtr> devices = enumerator->GetDevices();
   results_ = serial::GetDevices::Results::Create(
       devices.To<std::vector<linked_ptr<serial::DeviceInfo> > >());
-#endif
 }
 
 SerialConnectFunction::SerialConnectFunction() {
 }
 
 SerialConnectFunction::~SerialConnectFunction() {
 }
 
 bool SerialConnectFunction::Prepare() {
   params_ = serial::Connect::Params::Create(*args_);
@@ skipping 383 matching lines @@
   if (device->has_vendor_id)
     info->vendor_id.reset(new int(static_cast<int>(device->vendor_id)));
   if (device->has_product_id)
     info->product_id.reset(new int(static_cast<int>(device->product_id)));
   if (device->display_name)
     info->display_name.reset(new std::string(device->display_name));
   return info;
 }
 
 }  // namespace mojo