Portals: Add mojo interface.

This CL just adds an empty mojo interface that will be used for
implementing portals. The interface will be exposed by the browser in a
follow-up CL.

Bug: 865565
Change-Id: I1cd93aa19f83562b5f9dccfe3eb75c93433e6770
Reviewed-on: https://chromium-review.googlesource.com/1144054Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Lucas Gadani <lfg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578466}

third_party/blink/common/features.cc

@@ -40,5 +40,8 @@ const base::Feature kRecordAnchorMetricsClicked{
 const base::Feature kRecordAnchorMetricsVisible{
     "RecordAnchorMetricsVisible", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Enable Portals. https://crbug.com/865123.
+const base::Feature kPortals{"Portals", base::FEATURE_DISABLED_BY_DEFAULT};
+
 }  // namespace features
 }  // namespace blink

third_party/blink/public/common/features.h

@@ -19,6 +19,7 @@ BLINK_COMMON_EXPORT extern const base::Feature kServiceWorkerServicification;
 BLINK_COMMON_EXPORT extern const base::Feature kNestedWorkers;
 BLINK_COMMON_EXPORT extern const base::Feature kRecordAnchorMetricsClicked;
 BLINK_COMMON_EXPORT extern const base::Feature kRecordAnchorMetricsVisible;
+BLINK_COMMON_EXPORT extern const base::Feature kPortals;
 
 }  // namespace features
 }  // namespace blink

third_party/blink/public/mojom/BUILD.gn

@@ -101,6 +101,7 @@ mojom("speech_recognition_error_code") {
 mojom("mojom_core") {
   sources = [
     "message_port/message_port.mojom",
+    "portal/portal.mojom",
     "service_worker/service_worker.mojom",
     "service_worker/service_worker_object.mojom",
     "service_worker/service_worker_registration.mojom",

third_party/blink/public/mojom/portal/OWNERS

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

third_party/blink/public/mojom/portal/portal.mojom

+// Copyright 2018 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.
+
+module blink.mojom;
+
+// The Portal interface is used by the renderer to interact with the Portal.
+interface Portal {
+};