Implement basic USB device enumeration on Android.

device/usb/android/java/src/org/chromium/device/usb/ChromeUsbEndpoint.java

Index: device/usb/android/java/src/org/chromium/device/usb/ChromeUsbEndpoint.java
diff --git a/device/usb/android/java/src/org/chromium/device/usb/ChromeUsbEndpoint.java b/device/usb/android/java/src/org/chromium/device/usb/ChromeUsbEndpoint.java
new file mode 100644
index 0000000000000000000000000000000000000000..2359321fdb84a950b92698580a272c70fabdf761
--- /dev/null
+++ b/device/usb/android/java/src/org/chromium/device/usb/ChromeUsbEndpoint.java
@@ -0,0 +1,81 @@
+// 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.
+
+package org.chromium.device.usb;
+
+import android.hardware.usb.UsbConstants;
+import android.hardware.usb.UsbEndpoint;
+
+import org.chromium.base.Log;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+
+/**
+ * Exposes android.hardware.usb.UsbEndpoint as necessary for C++
+ * device::UsbEndpointAndroid.
+ *
+ * Lifetime is controlled by device::UsbEndpointAndroid.
+ */
+@JNINamespace("device")
+final class ChromeUsbEndpoint {
+    private static final String TAG = "Usb";
+
+    final UsbEndpoint mEndpoint;
+
+    private ChromeUsbEndpoint(UsbEndpoint endpoint) {
+        mEndpoint = endpoint;
+        Log.v(TAG, "ChromeUsbEndpoint created.");
+    }
+
+    @CalledByNative
+    private static ChromeUsbEndpoint create(UsbEndpoint endpoint) {
+        return new ChromeUsbEndpoint(endpoint);
+    }
+
+    @CalledByNative
+    private int getAddress() {
+        return mEndpoint.getAddress();
+    }
+
+    @CalledByNative
+    private int getDirection() {
+        switch (mEndpoint.getDirection()) {
+            case UsbConstants.USB_DIR_IN:
+                return UsbEndpointDirection.USB_DIRECTION_INBOUND;
+            case UsbConstants.USB_DIR_OUT:
+                return UsbEndpointDirection.USB_DIRECTION_OUTBOUND;
+        }
+        throw new AssertionError();

[qinmin, 2016/01/04 19:20:26]

you can move this to the switch statement's default:

[Reilly Grant (use Gerrit), 2016/01/05 01:35:29]

Done.

+    }
+
+    @CalledByNative
+    private int getMaxPacketSize() {
+        return mEndpoint.getMaxPacketSize();
+    }
+
+    @CalledByNative
+    private int getAttributes() {
+        return mEndpoint.getAttributes();
+    }
+
+    @CalledByNative
+    private int getType() {
+        switch (mEndpoint.getType()) {
+            case UsbConstants.USB_ENDPOINT_XFER_CONTROL:
+                return UsbTransferType.USB_TRANSFER_CONTROL;
+            case UsbConstants.USB_ENDPOINT_XFER_ISOC:
+                return UsbTransferType.USB_TRANSFER_ISOCHRONOUS;
+            case UsbConstants.USB_ENDPOINT_XFER_BULK:
+                return UsbTransferType.USB_TRANSFER_BULK;
+            case UsbConstants.USB_ENDPOINT_XFER_INT:
+                return UsbTransferType.USB_TRANSFER_INTERRUPT;
+        }
+        throw new AssertionError();

[qinmin, 2016/01/04 19:20:26]

ditto

[Reilly Grant (use Gerrit), 2016/01/05 01:35:29]

Done.

+    }
+
+    @CalledByNative
+    private int getInterval() {
+        return mEndpoint.getInterval();
+    }
+}