sample-swa: Use a WebUIConfig for the Sample System Web App untrusted context

Creates a WebUIConfig and WebUIController for the Sample System Web App's
untrusted context.

Bug: 1080384
Change-Id: I516339dd8b2412f377b460817d16fdb51146aefa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2592075
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: calamity <calamity@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837948}

chrome/browser/ui/webui/chrome_untrusted_web_ui_controller_factory.cc

@@ -13,6 +13,10 @@
 #include "ui/webui/webui_config.h"
 #include "url/gurl.h"
 
+#if BUILDFLAG(IS_CHROMEOS_ASH) && !defined(OFFICIAL_BUILD)
+#include "chromeos/components/sample_system_web_app_ui/untrusted_sample_system_web_app_ui.h"
+#endif
+
 using WebUIConfigList =
     std::vector<std::pair<std::string, std::unique_ptr<ui::WebUIConfig>>>;
 
@@ -24,18 +28,19 @@ namespace {
 // constructing from a vector is O(n log n).
 WebUIConfigList CreateConfigs() {
   WebUIConfigList config_list;
-#if BUILDFLAG(IS_CHROMEOS_ASH) && !defined(OFFICIAL_BUILD)
   auto register_config =
       [&config_list](std::unique_ptr<ui::WebUIConfig> config) {
         DCHECK_EQ(config->scheme(), content::kChromeUIUntrustedScheme);
         const std::string& host = config->host();
         config_list.emplace_back(host, std::move(config));
       };
+  // Delete once register_config is used outside of Chrome OS.
+  ALLOW_UNUSED_LOCAL(register_config);
 
   // Register WebUIConfigs below.
-
-  // TODO(ortuno): Remove when `register_config` is used to register configs.
-  DCHECK(&register_config);
+#if BUILDFLAG(IS_CHROMEOS_ASH) && !defined(OFFICIAL_BUILD)
+  register_config(
+      std::make_unique<chromeos::UntrustedSampleSystemWebAppUIConfig>());
 #endif
 
   return config_list;

chromeos/components/sample_system_web_app_ui/BUILD.gn

@@ -14,6 +14,8 @@ static_library("sample_system_web_app_ui") {
   sources = [
     "sample_system_web_app_ui.cc",
     "sample_system_web_app_ui.h",
+    "untrusted_sample_system_web_app_ui.cc",
+    "untrusted_sample_system_web_app_ui.h",
     "url_constants.cc",
     "url_constants.h",
   ]

chromeos/components/sample_system_web_app_ui/sample_system_web_app_ui.cc

@@ -17,18 +17,6 @@
 #include "ui/webui/webui_allowlist.h"
 
 namespace chromeos {
-namespace {
-content::WebUIDataSource* CreateUntrustedSampleSystemWebAppDataSource() {
-  content::WebUIDataSource* untrusted_source =
-      content::WebUIDataSource::Create(kChromeUIUntrustedSampleSystemWebAppURL);
-  untrusted_source->AddResourcePath(
-      "untrusted.html", IDR_CHROMEOS_SAMPLE_SYSTEM_WEB_APP_UNTRUSTED_HTML);
-  untrusted_source->AddResourcePath(
-      "untrusted.js", IDR_CHROMEOS_SAMPLE_SYSTEM_WEB_APP_UNTRUSTED_JS);
-  untrusted_source->AddFrameAncestor(GURL(kChromeUISampleSystemWebAppURL));
-  return untrusted_source;
-}
-}  // namespace
 
 SampleSystemWebAppUI::SampleSystemWebAppUI(content::WebUI* web_ui)
     : ui::MojoWebUIController(web_ui) {
@@ -58,8 +46,6 @@ SampleSystemWebAppUI::SampleSystemWebAppUI(content::WebUI* web_ui)
       network::mojom::CSPDirectiveName::FrameSrc, csp);
   auto* browser_context = web_ui->GetWebContents()->GetBrowserContext();
   content::WebUIDataSource::Add(browser_context, trusted_source.release());
-  content::WebUIDataSource::Add(browser_context,
-                                CreateUntrustedSampleSystemWebAppDataSource());
 
   // Add ability to request chrome-untrusted: URLs
   web_ui->AddRequestableScheme(content::kChromeUIUntrustedScheme);

chromeos/components/sample_system_web_app_ui/untrusted_sample_system_web_app_ui.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 "chromeos/components/sample_system_web_app_ui/untrusted_sample_system_web_app_ui.h"
+
+#include "chromeos/components/sample_system_web_app_ui/url_constants.h"
+#include "chromeos/grit/chromeos_sample_system_web_app_resources.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_ui.h"
+#include "content/public/browser/web_ui_data_source.h"
+#include "content/public/common/url_constants.h"
+#include "url/gurl.h"
+
+namespace chromeos {
+
+UntrustedSampleSystemWebAppUIConfig::UntrustedSampleSystemWebAppUIConfig()
+    : WebUIConfig(content::kChromeUIUntrustedScheme,
+                  kChromeUIUntrustedSampleSystemWebAppHost) {}
+
+UntrustedSampleSystemWebAppUIConfig::~UntrustedSampleSystemWebAppUIConfig() =
+    default;
+
+std::unique_ptr<content::WebUIController>
+UntrustedSampleSystemWebAppUIConfig::CreateWebUIController(
+    content::WebUI* web_ui) {
+  return std::make_unique<UntrustedSampleSystemWebAppUI>(web_ui);
+}
+
+UntrustedSampleSystemWebAppUI::UntrustedSampleSystemWebAppUI(
+    content::WebUI* web_ui)
+    : ui::UntrustedWebUIController(web_ui) {
+  content::WebUIDataSource* untrusted_source =
+      content::WebUIDataSource::Create(kChromeUIUntrustedSampleSystemWebAppURL);
+  untrusted_source->AddResourcePath(
+      "untrusted.html", IDR_CHROMEOS_SAMPLE_SYSTEM_WEB_APP_UNTRUSTED_HTML);
+  untrusted_source->AddResourcePath(
+      "untrusted.js", IDR_CHROMEOS_SAMPLE_SYSTEM_WEB_APP_UNTRUSTED_JS);
+  untrusted_source->AddFrameAncestor(GURL(kChromeUISampleSystemWebAppURL));
+
+#if !DCHECK_IS_ON()
+  // When DCHECKs are off and a user goes to an invalid url serve a default page
+  // to avoid crashing. We crash when DCHECKs are on to make it clearer that
+  // a resource path was not property specified.
+  untrusted_source->SetDefaultResource(
+      IDR_CHROMEOS_SAMPLE_SYSTEM_WEB_APP_UNTRUSTED_HTML);
+#endif  // !DCHECK_IS_ON()
+
+  auto* browser_context = web_ui->GetWebContents()->GetBrowserContext();
+  content::WebUIDataSource::Add(browser_context, untrusted_source);
+}
+
+UntrustedSampleSystemWebAppUI::~UntrustedSampleSystemWebAppUI() = default;
+
+}  // namespace chromeos

chromeos/components/sample_system_web_app_ui/untrusted_sample_system_web_app_ui.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 CHROMEOS_COMPONENTS_SAMPLE_SYSTEM_WEB_APP_UI_UNTRUSTED_SAMPLE_SYSTEM_WEB_APP_UI_H_
+#define CHROMEOS_COMPONENTS_SAMPLE_SYSTEM_WEB_APP_UI_UNTRUSTED_SAMPLE_SYSTEM_WEB_APP_UI_H_
+
+#include "ui/webui/untrusted_web_ui_controller.h"
+#include "ui/webui/webui_config.h"
+
+#if defined(OFFICIAL_BUILD)
+#error Sample System Web App should only be included in unofficial builds.
+#endif
+
+namespace content {
+class WebUI;
+}  // namespace content
+
+namespace chromeos {
+
+class UntrustedSampleSystemWebAppUIConfig : public ui::WebUIConfig {
+ public:
+  UntrustedSampleSystemWebAppUIConfig();
+  ~UntrustedSampleSystemWebAppUIConfig() override;
+
+  std::unique_ptr<content::WebUIController> CreateWebUIController(
+      content::WebUI* web_ui) override;
+};
+
+class UntrustedSampleSystemWebAppUI : public ui::UntrustedWebUIController {
+ public:
+  explicit UntrustedSampleSystemWebAppUI(content::WebUI* web_ui);
+  UntrustedSampleSystemWebAppUI(const UntrustedSampleSystemWebAppUI&) = delete;
+  UntrustedSampleSystemWebAppUI& operator=(
+      const UntrustedSampleSystemWebAppUI&) = delete;
+  ~UntrustedSampleSystemWebAppUI() override;
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_COMPONENTS_SAMPLE_SYSTEM_WEB_APP_UI_UNTRUSTED_SAMPLE_SYSTEM_WEB_APP_UI_H_

chromeos/components/sample_system_web_app_ui/url_constants.cc

@@ -8,6 +8,7 @@ namespace chromeos {
 
 const char kChromeUISampleSystemWebAppHost[] = "sample-system-web-app";
 const char kChromeUISampleSystemWebAppURL[] = "chrome://sample-system-web-app";
+const char kChromeUIUntrustedSampleSystemWebAppHost[] = "sample-system-web-app";
 const char kChromeUIUntrustedSampleSystemWebAppURL[] =
     "chrome-untrusted://sample-system-web-app/";
 

chromeos/components/sample_system_web_app_ui/url_constants.h

@@ -9,6 +9,7 @@ namespace chromeos {
 
 extern const char kChromeUISampleSystemWebAppHost[];
 extern const char kChromeUISampleSystemWebAppURL[];
+extern const char kChromeUIUntrustedSampleSystemWebAppHost[];
 extern const char kChromeUIUntrustedSampleSystemWebAppURL[];
 
 }  // namespace chromeos