Add unit tests for PolicyContainer

This change:
* adds some basic unit tests for content::PolicyContainer,
* creates a mock for the interface blink::mojom::PolicyContainerHost,
* uses that mock to unit test blink::PolicyContainer.

Bug: 1130587
Change-Id: If35e0b0c7099560f6a2de73fff6669274e00e9bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2440666
Commit-Queue: Antonio Sartori <antoniosartori@chromium.org>
Reviewed-by: Camille Lamy <clamy@chromium.org>
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Pâris Meuleman <pmeuleman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822601}

content/browser/renderer_host/policy_container_unittest.cc

+// Copyright 2020 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.
+
+#include "content/browser/renderer_host/policy_container.h"
+
+#include "services/network/public/mojom/referrer_policy.mojom-shared.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace content {
+
+TEST(PolicyContainerTest, ReferrerPolicy) {
+  PolicyContainer policy_container;
+  EXPECT_EQ(network::mojom::ReferrerPolicy::kDefault,
+            policy_container.referrer_policy());
+
+  static_cast<blink::mojom::PolicyContainerHost*>(&policy_container)
+      ->SetReferrerPolicy(network::mojom::ReferrerPolicy::kAlways);
+  EXPECT_EQ(network::mojom::ReferrerPolicy::kAlways,
+            policy_container.referrer_policy());
+}
+
+}  // namespace content

content/test/BUILD.gn

@@ -1939,6 +1939,7 @@ test("content_unittests") {
     "../browser/renderer_host/navigator_unittest.cc",
     "../browser/renderer_host/origin_policy_throttle_unittest.cc",
     "../browser/renderer_host/overscroll_controller_unittest.cc",
+    "../browser/renderer_host/policy_container_unittest.cc",
     "../browser/renderer_host/render_frame_host_feature_policy_unittest.cc",
     "../browser/renderer_host/render_frame_host_impl_unittest.cc",
     "../browser/renderer_host/render_frame_host_manager_unittest.cc",

third_party/blink/renderer/core/BUILD.gn

@@ -402,6 +402,8 @@ source_set("testing") {
     "testing/mock_clipboard_host.h",
     "testing/mock_hyphenation.cc",
     "testing/mock_hyphenation.h",
+    "testing/mock_policy_container_host.cc",
+    "testing/mock_policy_container_host.h",
     "testing/null_execution_context.cc",
     "testing/null_execution_context.h",
     "testing/origin_trials_test.cc",
@@ -426,6 +428,8 @@ source_set("testing") {
     "timing/internals_profiler.cc",
     "timing/internals_profiler.h",
   ]
+
+  public_deps = [ "//testing/gmock:gmock" ]
 }
 
 # core_bindings_generated ------------------------------------------------------
@@ -1278,6 +1282,7 @@ source_set("unit_tests") {
     "frame/mhtml_archive_test.cc",
     "frame/mhtml_loading_test.cc",
     "frame/performance_monitor_test.cc",
+    "frame/policy_container_test.cc",
     "frame/report_test.cc",
     "frame/reporting_context_test.cc",
     "frame/root_frame_viewport_test.cc",

third_party/blink/renderer/core/frame/policy_container_test.cc

+// Copyright 2020 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.
+
+#include "third_party/blink/renderer/core/frame/policy_container.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/renderer/core/testing/mock_policy_container_host.h"
+
+namespace blink {
+
+TEST(PolicyContainerTest, UpdateReferrerPolicyIsPropagated) {
+  MockPolicyContainerHost host;
+  auto policies = mojom::blink::PolicyContainerData::New(
+      network::mojom::blink::ReferrerPolicy::kAlways);
+  PolicyContainer policy_container(host.BindNewEndpointAndPassDedicatedRemote(),
+                                   std::move(policies));
+
+  EXPECT_CALL(host,
+              SetReferrerPolicy(network::mojom::blink::ReferrerPolicy::kNever));
+  policy_container.UpdateReferrerPolicy(
+      network::mojom::blink::ReferrerPolicy::kNever);
+  EXPECT_EQ(network::mojom::blink::ReferrerPolicy::kNever,
+            policy_container.GetReferrerPolicy());
+
+  // Wait for mojo messages to be received.
+  host.FlushForTesting();
+}
+
+}  // namespace blink

third_party/blink/renderer/core/testing/mock_policy_container_host.cc

+// Copyright 2020 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.
+
+#include "third_party/blink/renderer/core/testing/mock_policy_container_host.h"
+
+namespace blink {
+
+mojo::PendingAssociatedRemote<mojom::blink::PolicyContainerHost>
+MockPolicyContainerHost::BindNewEndpointAndPassDedicatedRemote() {
+  return receiver_.BindNewEndpointAndPassDedicatedRemote();
+}
+
+void MockPolicyContainerHost::FlushForTesting() {
+  receiver_.FlushForTesting();
+}
+
+}  // namespace blink

third_party/blink/renderer/core/testing/mock_policy_container_host.h

+// Copyright 2020 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 THIRD_PARTY_BLINK_RENDERER_CORE_TESTING_MOCK_POLICY_CONTAINER_HOST_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_TESTING_MOCK_POLICY_CONTAINER_HOST_H_
+
+#include "mojo/public/cpp/bindings/associated_receiver.h"
+#include "services/network/public/mojom/referrer_policy.mojom-shared.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "third_party/blink/public/mojom/frame/policy_container.mojom-blink.h"
+
+namespace blink {
+
+class MockPolicyContainerHost : public mojom::blink::PolicyContainerHost {
+ public:
+  MOCK_METHOD(void,
+              SetReferrerPolicy,
+              (network::mojom::ReferrerPolicy),
+              (override));
+  MockPolicyContainerHost() = default;
+
+  mojo::PendingAssociatedRemote<mojom::blink::PolicyContainerHost>
+  BindNewEndpointAndPassDedicatedRemote();
+  void FlushForTesting();
+
+ private:
+  mojo::AssociatedReceiver<mojom::blink::PolicyContainerHost> receiver_{this};
+};
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_TESTING_FAKE_POLICY_CONTAINER_HOST_H_