Revert of Implement basic USB device enumeration on Android.

device/usb/android/usb_jni_registrar.h

-// 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.
-
-#ifndef DEVICE_USB_ANDROID_USB_JNI_REGISTRAR_H_
-#define DEVICE_USB_ANDROID_USB_JNI_REGISTRAR_H_
-
-#include <jni.h>
-
-namespace device {
-namespace android {
-
-// Registers C++ methods in device/usb classes with JNI.
-// See https://www.chromium.org/developers/design-documents/android-jni
-//
-// Must be called before classes in the USB module are used.
-bool RegisterUsbJni(JNIEnv* env);
-
-}  // namespace android
-}  // namespace device
-
-#endif  // DEVICE_USB_ANDROID_USB_JNI_REGISTRAR_H_