Sync federated mojom files from Chromium OS side

Bug: 1125906
Test: None
Change-Id: I1da249ca0eac1bf81648ef2151e854c77df61b59
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2489124
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Andrew Moylan <amoylan@chromium.org>
Commit-Queue: Xinglong Luan <alanlxl@chromium.org>
Cr-Commit-Position: refs/heads/master@{#886116}

chromeos/services/federated/public/mojom/BUILD.gn

@@ -0,0 +1,14 @@
+# Copyright 2021 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.
+
+import("//mojo/public/tools/bindings/mojom.gni")
+
+mojom("mojom") {
+  sources = [
+    "example.mojom",
+    "federated_service.mojom",
+  ]
+
+  public_deps = [ "//mojo/public/mojom/base" ]
+}

chromeos/services/federated/public/mojom/OWNERS

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+per-file *.mojom=set noparent
+per-file *.mojom=file://ipc/SECURITY_OWNERS

chromeos/services/federated/public/mojom/example.mojom

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+// Copyright 2021 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.
+
+// Datatypes used in the Federated Service API.
+// This module is derived from the Feature and Example proto definition of
+// TensorFlow. See /tensorflow/core/example/feature.proto and
+// /tensorflow/core/example/example.proto in the TensorFlow code.
+
+// NOTE: This mojom should exist in two places and must be kept in sync:
+//       Chromium:  src/chromeos/services/federated/public/mojom/
+//       Chrome OS: src/platform2/federated/mojom/
+//       Note: Other repos downstream of Chromium might also use this mojom.
+// Example: A backwards-compatible mojom change (and corresponding
+// implementation change) can be made in Chrome OS first, then replicated to the
+// clients (Chromium, other downstream repos) later.
+// TODO(alanlxl): config a sync tool for federated mojo files.
+
+module chromeos.federated.mojom;
+
+struct StringList {
+  array<string> value;
+};
+
+struct FloatList {
+  array<double> value;
+};
+
+struct Int64List {
+  array<int64> value;
+};
+
+// The union of all supported value types.
+union ValueList {
+  StringList string_list;
+  FloatList float_list;
+  Int64List int64_list;
+};
+
+// The mirror of tensorflow::Features.
+struct Features {
+  // Map from feature name to feature.
+  map<string, ValueList> feature;
+};
+
+// The mirror of tensorflow::Example.
+struct Example {
+  Features features;
+};

chromeos/services/federated/public/mojom/federated_service.mojom

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+// Copyright 2021 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.
+
+// Top-level API of the Federated Service: report an example.
+
+// NOTE: This mojom should exist in two places and must be kept in sync:
+//       Chromium: //chromeos/services/federated/public/mojom
+//       Chrome OS: src/platform2/federated/mojom/
+
+module chromeos.federated.mojom;
+
+// NOTE: The base directory for 'import' statements is expected to differ
+//       between Chromium and Chrome OS versions of this file.
+import "chromeos/services/federated/public/mojom/example.mojom";
+
+// Top-level interface between Chromium and the Federated Service daemon.
+// Next ordinal: 2
+interface FederatedService {
+  // Binds another pipe to this instance.
+  Clone@0(pending_receiver<FederatedService> receiver);
+
+  // Stores `example` in cryptohome-backed storage for use during future
+  // scheduled federated analytics or ML model training, identified by
+  // `client_id`.
+  // Examples are deleted when they are used for federated analytics/training.
+  ReportExample@1(string client_name, Example example);
+};