Implement basic USB device enumeration on Android.

device/usb/usb_interface_android.cc

+// 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.
+
+#include "device/usb/usb_interface_android.h"
+
+#include "device/usb/usb_endpoint_android.h"
+#include "jni/ChromeUsbInterface_jni.h"
+
+using base::android::ScopedJavaLocalRef;
+
+namespace device {
+
+// static
+bool UsbInterfaceAndroid::RegisterJNI(JNIEnv* env) {
+  return RegisterNativesImpl(env);  // Generated in ChromeUsbInterface_jni.h
+}
+
+// static
+UsbInterfaceDescriptor UsbInterfaceAndroid::Convert(
+    JNIEnv* env,
+    const base::android::JavaRef<jobject>& usb_interface) {
+  ScopedJavaLocalRef<jobject> wrapper =
+      Java_ChromeUsbInterface_create(env, usb_interface.obj());
+
+  UsbInterfaceDescriptor interface;
+  interface.interface_number =
+      Java_ChromeUsbInterface_getInterfaceNumber(env, wrapper.obj());
+  interface.alternate_setting =
+      Java_ChromeUsbInterface_getAlternateSetting(env, wrapper.obj());
+  interface.interface_class =
+      Java_ChromeUsbInterface_getInterfaceClass(env, wrapper.obj());
+  interface.interface_subclass =
+      Java_ChromeUsbInterface_getInterfaceSubclass(env, wrapper.obj());
+  interface.interface_protocol =
+      Java_ChromeUsbInterface_getInterfaceProtocol(env, wrapper.obj());
+
+  ScopedJavaLocalRef<jobjectArray> endpoints =
+      Java_ChromeUsbInterface_getEndpoints(env, wrapper.obj());
+  jsize count = env->GetArrayLength(endpoints.obj());
+  interface.endpoints.reserve(count);
+  for (jsize i = 0; i < count; ++i) {
+    ScopedJavaLocalRef<jobject> endpoint(
+        env, env->GetObjectArrayElement(endpoints.obj(), i));
+    interface.endpoints.push_back(UsbEndpointAndroid::Convert(env, endpoint));
+  }
+
+  return interface;
+}
+
+}  // namespace device