memory-infra: Introduce mojo interfaces and service stubs

services/memory_infra/public/cpp/memory_infra_traits.h

+// Copyright 2017 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 SERVICES_MEMORY_INFRA_PUBLIC_CPP_MEMORY_INFRA_TRAITS_H_
+#define SERVICES_MEMORY_INFRA_PUBLIC_CPP_MEMORY_INFRA_TRAITS_H_
+
+#include "base/trace_event/memory_dump_request_args.h"
+#include "services/memory_infra/public/interfaces/memory_infra.mojom.h"
+
+namespace mojo {
+
+template<>

[Primiano Tucci (use gerrit), 2017/01/16 15:11:04]

(not related to your code, more about the mojo architecture)
it feels a bit odd that one has to manually wire up all this stuff. it seems to
me way more boilerplate from the previous IPC macros and hance more opportunity
to get this wrong.
But I also see that this is the way other pieces of the codebase seem to do
this, so I assume this is "the mojo way" of passing enums and structs. ¯\_(ツ)_/¯

[chiniforooshan1, 2017/01/16 18:14:48]

Ken, am I doing this correctly?

+struct EnumTraits<memory_infra::mojom::DumpType,
+                  base::trace_event::MemoryDumpType> {
+  static memory_infra::mojom::DumpType ToMojom(
+      base::trace_event::MemoryDumpType type);
+  static bool FromMojom(memory_infra::mojom::DumpType input,
+                        base::trace_event::MemoryDumpType* out);
+};
+
+template<>
+struct EnumTraits<memory_infra::mojom::LevelOfDetail,
+                  base::trace_event::MemoryDumpLevelOfDetail> {
+  static memory_infra::mojom::LevelOfDetail ToMojom(
+      base::trace_event::MemoryDumpLevelOfDetail level_of_detail);
+  static bool FromMojom(memory_infra::mojom::LevelOfDetail input,
+                        base::trace_event::MemoryDumpLevelOfDetail* out);
+};
+
+template<>
+struct StructTraits<memory_infra::mojom::RequestArgsDataView,
+                    base::trace_event::MemoryDumpRequestArgs> {
+  static uint64_t dump_guid(
+      const base::trace_event::MemoryDumpRequestArgs& args) {
+    return args.dump_guid;
+  }
+  static memory_infra::mojom::DumpType dump_type(
+      const base::trace_event::MemoryDumpRequestArgs& args);
+  static memory_infra::mojom::LevelOfDetail level_of_detail(
+      const base::trace_event::MemoryDumpRequestArgs& args);
+  static bool Read(memory_infra::mojom::RequestArgsDataView input,
+                   base::trace_event::MemoryDumpRequestArgs* out);
+};
+
+}  // namespace mojo
+
+#endif  // SERVICES_MEMORY_INFRA_PUBLIC_CPP_MEMORY_INFRA_TRAITS_H_