Add WebUSB bindings and client interface

Source/modules/webusb/USBEndpoint.cpp

Index: Source/modules/webusb/USBEndpoint.cpp
diff --git a/Source/modules/webusb/USBEndpoint.cpp b/Source/modules/webusb/USBEndpoint.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..471c6b7c07f4df82ea545bf618568f6780d66251
--- /dev/null
+++ b/Source/modules/webusb/USBEndpoint.cpp
@@ -0,0 +1,89 @@
+// 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 "config.h"
+#include "modules/webusb/USBEndpoint.h"
+
+#include "modules/webusb/USBAlternateInterface.h"
+#include "public/platform/modules/webusb/WebUSBDevice.h"
+
+namespace blink {
+
+namespace {
+
+String ConvertDirection(const WebUSBDevice::TransferDirection& direction)
+{
+    switch (direction) {
+    case WebUSBDevice::TransferDirectionIn:
+        return "in";
+    case WebUSBDevice::TransferDirectionOut:
+        return "out";
+    default:
+        ASSERT_NOT_REACHED();

[Reilly Grant (use Gerrit), 2015/07/23 23:24:08]

If you can convince the compiler these switch statements are exhaustive that
would be awesome.

[Ken Rockot(use gerrit already), 2015/07/28 22:30:38]

Acknowledged. I don't think that's realistic without enum classes though. Even
if you can convince the compiler, it's easy to lie. Mimicking this pattern from
other blink code.

+        return "";
+    }
+}
+
+String ConvertType(const WebUSBDeviceInfo::Endpoint::Type& type)
+{
+    switch (type) {
+    case WebUSBDeviceInfo::Endpoint::TypeBulk:
+        return "bulk";
+    case WebUSBDeviceInfo::Endpoint::TypeInterrupt:
+        return "interrupt";
+    case WebUSBDeviceInfo::Endpoint::TypeIsochronous:
+        return "isochronous";
+    default:
+        ASSERT_NOT_REACHED();
+        return "";
+    }
+}
+
+} // namespace
+
+// static
+USBEndpoint* USBEndpoint::create(const USBAlternateInterface* alternate, size_t endpointIndex)
+{
+    return new USBEndpoint(alternate, endpointIndex);
+}
+
+USBEndpoint::USBEndpoint(const USBAlternateInterface* alternate, size_t endpointIndex)
+    : m_alternate(alternate)
+    , m_endpointIndex(endpointIndex)
+{
+}
+
+const WebUSBDeviceInfo::Endpoint& USBEndpoint::info() const
+{
+    const WebUSBDeviceInfo::AlternateInterface& alternateInfo = m_alternate->info();
+    ASSERT(m_endpointIndex < alternateInfo.endpoints.size());
+    return alternateInfo.endpoints[m_endpointIndex];
+}
+
+uint8_t USBEndpoint::endpointNumber() const
+{
+    return info().endpointNumber;
+}
+
+String USBEndpoint::direction() const
+{
+    return ConvertDirection(info().direction);
+}
+
+String USBEndpoint::type() const
+{
+    return ConvertType(info().type);
+}
+
+unsigned USBEndpoint::packetSize() const
+{
+    return info().packetSize;
+}
+
+DEFINE_TRACE(USBEndpoint)
+{
+    visitor->trace(m_alternate);
+}
+
+} // namespace blink