Introducing gpu::CommandBufferId as a distinct, IdType<...>-based type.

gpu/ipc/id_type_traits.h

Index: gpu/ipc/id_type_traits.h
diff --git a/gpu/ipc/id_type_traits.h b/gpu/ipc/id_type_traits.h
new file mode 100644
index 0000000000000000000000000000000000000000..7857a1f528a3091905dc8f2f07a1216728bd1ab4
--- /dev/null
+++ b/gpu/ipc/id_type_traits.h
@@ -0,0 +1,43 @@
+// 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 GPU_IPC_ID_TYPE_TRAITS_H_
+#define GPU_IPC_ID_TYPE_TRAITS_H_
+
+#include <string>
+
+#include "base/pickle.h"
+#include "gpu/command_buffer/common/id_type.h"
+#include "ipc/ipc_message_utils.h"
+#include "ipc/ipc_param_traits.h"
+
+namespace IPC {
+
+template <typename TypeMarker, typename WrappedType, WrappedType kInvalidValue>
+struct ParamTraits<gpu::IdType<TypeMarker, WrappedType, kInvalidValue>> {
+  typedef gpu::IdType<TypeMarker, WrappedType, kInvalidValue> param_type;

[dcheng, 2016/02/12 19:23:17]

using param_type = gpu::IdType<TypeMarker, WrappedType, kInvalidValue>;

[Łukasz Anforowicz, 2016/02/12 22:33:24]

Done - good point (my poor excuse for not doing it earlier is that previously it
was matching the style of other nearby code in ipc_message_utils.h - I should
have changed to "using" after moving this code to id_type_traits.h).

+  typedef ParamTraits<WrappedType> base_param_traits;
+  static void GetSize(base::PickleSizer* sizer, const param_type& p) {
+    base_param_traits::GetSize(sizer, p.GetUnsafeValue());

[dcheng, 2016/02/12 19:23:17]

Use the type deducing helpers =)

GetParamSize(sizer, p.GetUnsafeValue())

[Łukasz Anforowicz, 2016/02/12 22:33:24]

Doh... thanks!

Done (I also removed no longer needed |base_param_traits| type alias).

+  }
+  static void Write(base::Pickle* m, const param_type& p) {
+    base_param_traits::Write(m, p.GetUnsafeValue());

[dcheng, 2016/02/12 19:23:17]

WriteParam(m, p.GetUnsafeValue()

[Łukasz Anforowicz, 2016/02/12 22:33:24]

Done.

+  }
+  static bool Read(const base::Pickle* m,
+                   base::PickleIterator* iter,
+                   param_type* r) {
+    WrappedType value;
+    if (!base_param_traits::Read(m, iter, &value))

[dcheng, 2016/02/12 19:23:17]

ReadParam(m, iter, &value)

[Łukasz Anforowicz, 2016/02/12 22:33:24]

Done.

+      return false;
+    *r = param_type::FromUnsafeValue(value);
+    return true;
+  }
+  static void Log(const param_type& p, std::string* l) {
+    base_param_traits::Log(p.GetUnsafeValue(), l);

[dcheng, 2016/02/12 19:23:17]

LogParam(p.getUnsafeValue(), l)

[Łukasz Anforowicz, 2016/02/12 22:33:24]

Done.

+  }
+};
+
+}  // namespace IPC
+
+#endif  // GPU_IPC_ID_TYPE_TRAITS_H_