bluetooth: Use BluetoothUUID instead of string when sending uuids

device/bluetooth/mojo/bluetooth_uuid_struct_traits.h

+// Copyright 2016 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_BLUETOOTH_MOJO_BLUETOOTH_UUID_STRUCT_TRAITS_H_
+#define DEVICE_BLUETOOTH_MOJO_BLUETOOTH_UUID_STRUCT_TRAITS_H_
+
+#include "base/strings/string_piece.h"
+#include "device/bluetooth/bluetooth_uuid.h"
+#include "device/bluetooth/mojo/bluetooth_uuid.mojom.h"
+
+namespace mojo {
+
+template <>
+struct StructTraits<device::mojom::BluetoothUUID,
+                    std::unique_ptr<device::BluetoothUUID>> {
+  static bool IsNull(const std::unique_ptr<device::BluetoothUUID>& uuid) {
+    return !uuid.get();

[Ken Rockot(use gerrit already), 2016/05/26 21:05:07]

nit: !uuid should be sufficient

[ortuno, 2016/05/27 14:38:36]

Done.

+  }
+
+  static void SetToNull(std::unique_ptr<device::BluetoothUUID>* output) {
+    *output = nullptr;

[Ken Rockot(use gerrit already), 2016/05/26 21:05:07]

optional style/opinion nit: perhaps output->reset() would be more readable

[ortuno, 2016/05/27 14:38:36]

Done.

+  }
+
+  static base::StringPiece uuid(
+      const std::unique_ptr<device::BluetoothUUID>& uuid) {
+    DCHECK(uuid.get());

[Ken Rockot(use gerrit already), 2016/05/26 21:05:07]

nit: DCHECK(uuid) should be sufficient

[ortuno, 2016/05/27 14:38:36]

Done.

+    return base::StringPiece(uuid->canonical_value().c_str(),
+                             uuid->canonical_value().length());
+  }
+
+  static bool Read(device::mojom::BluetoothUUIDDataView input,
+                   std::unique_ptr<device::BluetoothUUID>* output) {
+    base::StringPiece result;
+    if (!input.ReadUuid(&result))
+      return false;
+    *output = base::WrapUnique(new device::BluetoothUUID(result.as_string()));
+
+    // If the format isn't 128-bit, .value() would return a different answer
+    // than .canonical_value(). Then if browser-side code accidentally checks
+    // .value() against a 128-bit string literal, a hostile renderer could use
+    // the 16- or 32-bit format and evade the check.
+    return (*output)->IsValid() &&
+           (*output)->format() == device::BluetoothUUID::kFormat128Bit;
+  }
+};
+}
+
+#endif  // DEVICE_BLUETOOTH_MOJO_BLUETOOTH_UUID_STRUCT_TRAITS_H_