feedback: Add skeleton and build plumbing for help content provider

- Adds backend class skeleton
- Adds simple unit test
- Add build plumbing for tests and code

Bug: b:185624798
Test: ash_webui_unittests --gtest_filter="HelpContentProviderTest.*"
Change-Id: Iea87eb1588eea5d3734bc1fdf7d332723d3cf72f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3451178
Reviewed-by: Jimmy Gong <jimmyxgong@chromium.org>
Commit-Queue: Xiangdong Kong <xiangdongkong@google.com>
Cr-Commit-Position: refs/heads/main@{#969789}

ash/webui/BUILD.gn

@@ -27,6 +27,7 @@ test("ash_webui_unittests") {
     "//ash/webui/eche_app_ui:unit_tests",
     "//ash/webui/file_manager:unit_tests",
     "//ash/webui/help_app_ui:unit_tests",
+    "//ash/webui/os_feedback_ui/backend:unit_tests",
     "//ash/webui/projector_app:unit_tests",
     "//ash/webui/scanning:unit_tests",
     "//ash/webui/shimless_rma/backend:unit_tests",

ash/webui/os_feedback_ui/BUILD.gn

@@ -18,6 +18,7 @@ static_library("os_feedback_ui") {
   ]
 
   deps = [
+    "//ash/webui/os_feedback_ui/backend",
     "//ash/webui/resources:os_feedback_resources",
     "//ash/webui/resources:os_feedback_untrusted_resources",
     "//content/public/browser",

ash/webui/os_feedback_ui/backend/BUILD.gn

@@ -0,0 +1,28 @@
+# Copyright 2022 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("//build/config/chromeos/ui_mode.gni")
+
+assert(is_chromeos_ash, "Non-ChromeOS builds cannot depend on //ash")
+
+static_library("backend") {
+  sources = [
+    "help_content_provider.cc",
+    "help_content_provider.h",
+  ]
+
+  deps = []
+}
+
+source_set("unit_tests") {
+  testonly = true
+
+  sources = [ "help_content_provider_unittest.cc" ]
+
+  deps = [
+    ":backend",
+    "//base/test:test_support",
+    "//testing/gtest",
+  ]
+}

ash/webui/os_feedback_ui/backend/help_content_provider.cc

@@ -0,0 +1,14 @@
+// Copyright 2022 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 "ash/webui/os_feedback_ui/backend/help_content_provider.h"
+
+namespace ash {
+namespace feedback {
+
+HelpContentProvider::HelpContentProvider() = default;
+HelpContentProvider::~HelpContentProvider() = default;
+
+}  // namespace feedback
+}  // namespace ash

ash/webui/os_feedback_ui/backend/help_content_provider.h

@@ -0,0 +1,22 @@
+// Copyright 2022 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 ASH_WEBUI_OS_FEEDBACK_UI_BACKEND_HELP_CONTENT_PROVIDER_H_
+#define ASH_WEBUI_OS_FEEDBACK_UI_BACKEND_HELP_CONTENT_PROVIDER_H_
+
+namespace ash {
+namespace feedback {
+
+class HelpContentProvider {
+ public:
+  HelpContentProvider();
+  HelpContentProvider(const HelpContentProvider&) = delete;
+  HelpContentProvider& operator=(const HelpContentProvider&) = delete;
+  ~HelpContentProvider();
+};
+
+}  // namespace feedback
+}  // namespace ash
+
+#endif  // ASH_WEBUI_OS_FEEDBACK_UI_BACKEND_HELP_CONTENT_PROVIDER_H_

ash/webui/os_feedback_ui/backend/help_content_provider_unittest.cc

@@ -0,0 +1,24 @@
+// Copyright 2022 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 "ash/webui/os_feedback_ui/backend/help_content_provider.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace ash {
+namespace feedback {
+
+class HelpContentProviderTest : public testing::Test {
+ public:
+  HelpContentProviderTest() = default;
+  ~HelpContentProviderTest() override = default;
+};
+
+TEST_F(HelpContentProviderTest, DummyTest) {
+  HelpContentProvider provider;
+  EXPECT_TRUE(true);
+}
+
+}  // namespace feedback
+}  // namespace ash