Convert utility process out-of-process file patching to mojo

chrome/common/file_patcher.mojom

+// 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.
+
+// File patching interface provided by the utility process and exposed
+// via mojo policy control to the chrome browser process.
+
+module chrome.mojom;
+
+import "mojo/common/file.mojom";
+
+interface FilePatcher {
+  // Patch |input_file| with |patch_file| using the bsdiff algorithm
+  // (Courgette's version) and place the output in |output_file|.
+  // Returns |result| bsdiff::OK on success.

[tibell, 2016/12/22 02:59:38]

Nit: perhaps worth saying that |result| is a |bsdiff::BSDiffStatus|.

+  PatchFileBsdiff(
+      mojo.common.mojom.File input_file,
+      mojo.common.mojom.File patch_file,
+      mojo.common.mojom.File output_file) => (int32 result);
+
+  // Patch |input_file| with |patch_file| using the Courgette algorithm
+  // and place the output in |output_file|.
+  // Returns |result| courgette::C_OK on success.
+  PatchFileCourgette(
+      mojo.common.mojom.File input_file,
+      mojo.common.mojom.File patch_file,
+      mojo.common.mojom.File output_file) => (int32 result);

[tibell, 2016/12/22 02:59:38]

Nit: perhaps worth saying that |result| is a |courgette::Status|.

+};