Implement basic USB device enumeration on Android.

device/test/run_all_unittests.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 "base/bind.h"
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
 #include "third_party/mojo/src/mojo/edk/embedder/embedder.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/jni_android.h"
 #include "device/bluetooth/android/bluetooth_jni_registrar.h"
+#include "device/usb/android/usb_jni_registrar.h"
 #endif
 
 int main(int argc, char** argv) {
 #if defined(OS_ANDROID)
   device::android::RegisterBluetoothJni(base::android::AttachCurrentThread());
+  device::android::RegisterUsbJni(base::android::AttachCurrentThread());
 #endif
 
   base::TestSuite test_suite(argc, argv);
 
   mojo::embedder::Init();
   return base::LaunchUnitTests(
       argc,
       argv,
       base::Bind(&base::TestSuite::Run, base::Unretained(&test_suite)));
 }