Scaffolding for ChromeOS chrome://media-app and chrome://media-app-guest.

Installs these routes as webui with basic structure and no permissions.

Code added as a component in //chromeos/components/media_app_ui so that
any chrome dependencies are clearly documented.

--enable-features=MediaApp is required to enable the app at runtime on
ChromeOS. The app is loaded as a guest (currently in an <iframe>) hosted
in another chrome:// WebUI host that may be granted privileges in
future. Currently the WebUI loaded in the <iframe> uses a chrome://
scheme, but this is not the long-term plan.

A js2gtest is added with a test fixture that enables these flags and
does integration testing.

A build-time flag, enable_cros_media_app determines the bulk of what is
served inside the sandboxed guest. When false, it provides a mock that
facilitates integration testing even when is_chrome_branded is false. An
internal change - https://crrev.com/i/1646974 - provides the content
when is_chrome_branded is true (enable_cros_media_app must be set
manually in args.gn until that lands).

Bug: 996088
Change-Id: Ied7a41795409bdc8c028e63155f37452be84532e
Test: MediaAppUIBrowserTest.WebviewHasAppElement
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1767457
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Dan Beam <dbeam@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697850}

chrome/browser/ui/BUILD.gn

@@ -1912,6 +1912,7 @@ jumbo_split_static_library("ui") {
       "//chromeos/assistant:buildflags",
       "//chromeos/audio",
       "//chromeos/components/account_manager",
+      "//chromeos/components/media_app_ui",
       "//chromeos/components/multidevice",
       "//chromeos/components/multidevice/debug_webui",
       "//chromeos/components/multidevice/logging",

chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc

@@ -183,6 +183,9 @@
 #include "chrome/browser/ui/webui/chromeos/terminal/terminal_ui.h"
 #include "chrome/browser/ui/webui/settings/chromeos/os_settings_ui.h"
 #include "chrome/browser/ui/webui/signin/inline_login_ui.h"
+#include "chromeos/components/media_app_ui/media_app_guest_ui.h"
+#include "chromeos/components/media_app_ui/media_app_ui.h"
+#include "chromeos/components/media_app_ui/url_constants.h"
 #include "chromeos/components/multidevice/debug_webui/proximity_auth_ui.h"
 #include "chromeos/components/multidevice/debug_webui/url_constants.h"
 #include "chromeos/constants/chromeos_features.h"
@@ -559,6 +562,12 @@ WebUIFactoryFunction GetWebUIFactoryFunction(WebUI* web_ui,
     return &NewWebUI<chromeos::settings::OSSettingsUI>;
   if (url.host_piece() == chrome::kChromeUIPowerHost)
     return &NewWebUI<chromeos::PowerUI>;
+  if (base::FeatureList::IsEnabled(chromeos::features::kMediaApp)) {
+    if (url.host_piece() == chromeos::kChromeUIMediaAppHost)
+      return &NewWebUI<chromeos::MediaAppUI>;
+    if (url.host_piece() == chromeos::kChromeUIMediaAppGuestHost)
+      return &NewWebUI<chromeos::MediaAppGuestUI>;
+  }
   if (url.host_piece() == chromeos::multidevice::kChromeUIProximityAuthHost)
     return &NewWebUI<chromeos::multidevice::ProximityAuthUI>;
   if (url.host_piece() == chrome::kChromeUIInternetConfigDialogHost)

chrome/test/BUILD.gn

@@ -1434,6 +1434,9 @@ if (!is_android) {
         "//chrome/test/data/webui:browser_tests_js_mojo_lite_webui",
         "//chrome/test/data/webui:browser_tests_js_webui",
       ]
+      if (is_chromeos) {
+        deps += [ "//chromeos/components/media_app_ui:browser_tests_js" ]
+      }
     }
 
     if (!is_fuchsia) {

chromeos/components/media_app_ui/BUILD.gn

+# Copyright 2019 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("//chrome/test/base/js2gtest.gni")
+
+assert(is_chromeos, "Media App is Chrome OS only")
+
+static_library("media_app_ui") {
+  sources = [
+    "media_app_guest_ui.cc",
+    "media_app_guest_ui.h",
+    "media_app_ui.cc",
+    "media_app_ui.h",
+    "url_constants.cc",
+    "url_constants.h",
+  ]
+
+  deps = [
+    "//chromeos/constants",
+    "//chromeos/resources",
+    "//content/public/browser",
+    "//ui/webui",
+  ]
+}
+
+js2gtest("browser_tests_js") {
+  test_type = "mojo_lite_webui"
+
+  sources = [
+    "test/media_app_ui_browsertest.js",
+  ]
+
+  defines = [ "HAS_OUT_OF_PROC_TEST_RUNNER" ]
+
+  deps = [
+    "//chromeos/constants",
+  ]
+}

chromeos/components/media_app_ui/DEPS

+include_rules = [
+  # Do not add chrome here (use a delegate instead).
+  "+chromeos/grit/chromeos_resources.h",
+  "+content/public/browser",
+  "+ui/webui",
+]

chromeos/components/media_app_ui/OWNERS

+tapted@chromium.org

chromeos/components/media_app_ui/README

+Provides the chrome://media-app WebUI and supporting interfaces that allow the
+Media App to integrate with ChromeOS.
+
+The bulk of the UI is provided by an internal CIPD package via DEPS, which is
+then served via the resource bundle. See go/media-app for the internal source.

chromeos/components/media_app_ui/media_app_guest_ui.cc

+// Copyright 2019 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/media_app_ui/media_app_guest_ui.h"
+
+#include "chromeos/components/media_app_ui/url_constants.h"
+#include "chromeos/grit/chromeos_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"
+
+namespace chromeos {
+
+// static
+content::WebUIDataSource* MediaAppGuestUI::CreateDataSource() {
+  content::WebUIDataSource* source =
+      content::WebUIDataSource::Create(kChromeUIMediaAppGuestHost);
+  source->AddResourcePath("app.html", IDR_MEDIA_APP_APP_HTML);
+  source->AddResourcePath("js/app_main.js", IDR_MEDIA_APP_APP_JS);
+  source->AddResourcePath("js/app_image_handler_module.js",
+                          IDR_MEDIA_APP_IMAGE_HANDLER_MODULE_JS);
+  source->AddResourcePath("js/app_drop_target_module.js",
+                          IDR_MEDIA_APP_DROP_TARGET_MODULE_JS);
+  return source;
+}
+
+MediaAppGuestUI::MediaAppGuestUI(content::WebUI* web_ui)
+    : MojoWebUIController(web_ui) {
+  content::WebUIDataSource::Add(web_ui->GetWebContents()->GetBrowserContext(),
+                                CreateDataSource());
+}
+
+MediaAppGuestUI::~MediaAppGuestUI() = default;
+
+}  // namespace chromeos

chromeos/components/media_app_ui/media_app_guest_ui.h

+// Copyright 2019 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_MEDIA_APP_UI_MEDIA_APP_GUEST_UI_H_
+#define CHROMEOS_COMPONENTS_MEDIA_APP_UI_MEDIA_APP_GUEST_UI_H_
+
+#include "base/macros.h"
+#include "ui/webui/mojo_web_ui_controller.h"
+
+namespace content {
+class WebUIDataSource;
+}
+
+namespace chromeos {
+
+// The WebUI controller for chrome://media-app-guest.
+class MediaAppGuestUI : public ui::MojoWebUIController {
+ public:
+  static content::WebUIDataSource* CreateDataSource();
+
+  explicit MediaAppGuestUI(content::WebUI* web_ui);
+  ~MediaAppGuestUI() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MediaAppGuestUI);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_COMPONENTS_MEDIA_APP_UI_MEDIA_APP_GUEST_UI_H_

chromeos/components/media_app_ui/media_app_ui.cc

+// Copyright 2019 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/media_app_ui/media_app_ui.h"
+
+#include "chromeos/components/media_app_ui/media_app_guest_ui.h"
+#include "chromeos/components/media_app_ui/url_constants.h"
+#include "chromeos/grit/chromeos_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"
+
+namespace chromeos {
+namespace {
+
+content::WebUIDataSource* CreateHostDataSource() {
+  content::WebUIDataSource* source =
+      content::WebUIDataSource::Create(kChromeUIMediaAppHost);
+  source->SetDefaultResource(IDR_MEDIA_APP_INDEX_HTML);
+  return source;
+}
+
+}  // namespace
+
+MediaAppUI::MediaAppUI(content::WebUI* web_ui) : MojoWebUIController(web_ui) {
+  content::BrowserContext* browser_context =
+      web_ui->GetWebContents()->GetBrowserContext();
+  content::WebUIDataSource* host_source = CreateHostDataSource();
+  content::WebUIDataSource::Add(browser_context, host_source);
+
+  // Whilst the guest is in an <iframe> rather than a <webview>, we need a CSP
+  // override to use the guest origin in the host.
+  // TODO(crbug/996088): Remove these overrides when there's a new sandboxing
+  // option for the guest.
+  std::string csp = std::string("frame-src ") + kChromeUIMediaAppGuestURL + ";";
+  host_source->OverrideContentSecurityPolicyChildSrc(csp);
+
+  // We also add the guest data source here (and allow it to be iframed). If
+  // it's only added in the MediaAppGuestUI constructor, then a user navigation
+  // to chrome://media-app-guest is required before the <iframe> can see it.
+  // This is due to logic in RenderFrameHostManager::GetFrameHostForNavigation()
+  // that currently skips creating webui objects when !IsMainFrame() (which is
+  // temporary according to https://crbug.com/713313 but, long-term, the guest
+  // shouldn't need the webui objects in any case - just the data source).
+  content::WebUIDataSource* guest_source = MediaAppGuestUI::CreateDataSource();
+  guest_source->DisableDenyXFrameOptions();
+  content::WebUIDataSource::Add(browser_context, guest_source);
+}
+
+MediaAppUI::~MediaAppUI() = default;
+
+}  // namespace chromeos

chromeos/components/media_app_ui/media_app_ui.gni

+import("//build/config/chrome_build.gni")
+
+declare_args() {
+  # Whether to enable the "real" ChromeOS Media App. When false, a mock app is
+  # bundled for testing integration points.
+  # TODO(crbug/996088): Change this to is_chromeos && is_chrome_branded.
+  enable_cros_media_app = false
+}

chromeos/components/media_app_ui/media_app_ui.h

+// Copyright 2019 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_MEDIA_APP_UI_MEDIA_APP_UI_H_
+#define CHROMEOS_COMPONENTS_MEDIA_APP_UI_MEDIA_APP_UI_H_
+
+#include "base/macros.h"
+#include "ui/webui/mojo_web_ui_controller.h"
+
+namespace chromeos {
+
+// The WebUI controller for chrome://media-app.
+class MediaAppUI : public ui::MojoWebUIController {
+ public:
+  explicit MediaAppUI(content::WebUI* web_ui);
+  ~MediaAppUI() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MediaAppUI);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_COMPONENTS_MEDIA_APP_UI_MEDIA_APP_UI_H_

chromeos/components/media_app_ui/resources/app.html

+<!-- Copyright 2019 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. -->
+<!DOCTYPE html>
+<style>
+  body {
+    overflow: hidden;
+    margin: 0;
+  }
+</style>
+<backlight-app></backlight-app>
+<script src="/js/app_main.js"></script>
+<!-- TODO(crbug/996088): Include scripts to run in the <webview> sandbox that
+     communicate via postMessage to scripts running in index.html -->

chromeos/components/media_app_ui/resources/index.html

+<!-- Copyright 2019 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. -->
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Media App</title>
+<style>
+  body {
+    height: 100vh;
+    margin: 0;
+    overflow: hidden;
+  }
+  /*
+   * This is the <iframe> style set for sandboxed guests that use
+   * guest_view_iframe_container.js.
+   * TODO(crbug/996088): Remove the iframe styles if switched to <webview>.
+   */
+  iframe {
+    border: 0;
+    height: 100%;
+    width: 100%;
+  }
+</style>
+<script src="chrome://resources/mojo/mojo/public/js/mojo_bindings_lite.js"></script>
+<iframe src="chrome://media-app-guest/app.html"></iframe>
+<!-- TODO(crbug/996088): Include scripts running with privileges necessary to
+     provide functionality to the sandboxed guest. -->

chromeos/components/media_app_ui/resources/mock/js/app_main.js

+// Copyright 2019 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.
+
+/**
+ * @fileoverview
+ * Provides a mock of http://go/media-app/index.ts which is pre-built and
+ * brought in via DEPS to ../../app/js/app_main.js. Runs in an isolated guest.
+ */

chromeos/components/media_app_ui/resources/mock/js/mock_module.js

+// Copyright 2019 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.
+
+/**
+ * @fileoverview
+ * An empty script used when mocking that provides no functionality, but avoids
+ * a 404 error.
+ */

chromeos/components/media_app_ui/test/DEPS

+include_rules = [
+  # Tests run in browser_tests, so can access things under chrome/test/base*.
+  "+chrome/test/base",
+]

chromeos/components/media_app_ui/test/media_app_ui_browsertest.js

+// Copyright 2019 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.
+
+/**
+ * @fileoverview Test suite for chrome://media-app.
+ */
+
+GEN('#include "chromeos/constants/chromeos_features.h"');
+
+const HOST_ORIGIN = 'chrome://media-app';
+const GUEST_SRC = 'chrome://media-app-guest/app.html';
+
+var MediaAppUIBrowserTest = class extends testing.Test {
+  /** @override */
+  get browsePreload() {
+    return HOST_ORIGIN;
+  }
+
+  /** @override */
+  get featureList() {
+    return {enabled: ['chromeos::features::kMediaApp']};
+  }
+
+  /** @override */
+  get runAccessibilityChecks() {
+    return false;
+  }
+};
+
+// Tests that chrome://media-app is allowed to frame chrome://media-app-guest.
+// The URL is set in the html. If that URL can't load, test this fails like JS
+// ERROR: "Refused to frame '...' because it violates the following Content
+// Security Policy directive: "frame-src chrome://media-app-guest/".
+// This test also fails if the guest renderer is terminated, e.g., due to webui
+// performing bad IPC such as network requests (failure detected in
+// content/public/test/no_renderer_crashes_assertion.cc).
+TEST_F('MediaAppUIBrowserTest', 'GuestCanLoad', () => {
+  const guest = document.querySelector('iframe');
+
+  assertEquals(document.location.origin, HOST_ORIGIN);
+  assertEquals(guest.src, GUEST_SRC);
+});
+
+// TODO(crbug/996088): Add Tests that inspect the guest itself. Until the guest
+// listens for postMessage calls, we can't test for anything interesting due to
+// CORS (i.e. "Blocked a frame with origin chrome://media-app from accessing a
+// cross-origin frame.").

chromeos/components/media_app_ui/url_constants.cc

+// Copyright 2019 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/media_app_ui/url_constants.h"
+
+namespace chromeos {
+
+const char kChromeUIMediaAppHost[] = "media-app";
+const char kChromeUIMediaAppURL[] = "chrome://media-app/";
+const char kChromeUIMediaAppGuestHost[] = "media-app-guest";
+const char kChromeUIMediaAppGuestURL[] = "chrome://media-app-guest/";
+
+}  // namespace chromeos

chromeos/components/media_app_ui/url_constants.h

+// Copyright 2019 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_MEDIA_APP_UI_URL_CONSTANTS_H_
+#define CHROMEOS_COMPONENTS_MEDIA_APP_UI_URL_CONSTANTS_H_
+
+namespace chromeos {
+
+extern const char kChromeUIMediaAppHost[];
+extern const char kChromeUIMediaAppURL[];
+extern const char kChromeUIMediaAppGuestHost[];
+extern const char kChromeUIMediaAppGuestURL[];
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_COMPONENTS_MEDIA_APP_UI_URL_CONSTANTS_H_

chromeos/constants/chromeos_features.cc

@@ -146,6 +146,9 @@ const base::Feature kImeDecoderWithSandbox{"ImeDecoderWithSandbox",
 const base::Feature kInstantTethering{"InstantTethering",
                                       base::FEATURE_DISABLED_BY_DEFAULT};
 
+// ChromeOS Media App. https://crbug.com/996088.
+const base::Feature kMediaApp{"MediaApp", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Controls whether to enable the Parental Controls section of settings.
 const base::Feature kParentalControlsSettings{
     "ChromeOSParentalControlsSettings", base::FEATURE_DISABLED_BY_DEFAULT};

chromeos/constants/chromeos_features.h

@@ -70,6 +70,7 @@ COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const base::Feature kImeDecoderWithSandbox;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const base::Feature kInstantTethering;
+COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const base::Feature kMediaApp;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const base::Feature kParentalControlsSettings;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)

chromeos/resources/BUILD.gn

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 import("//chromeos/assistant/assistant.gni")
+import("//chromeos/components/media_app_ui/media_app_ui.gni")
 import("//tools/grit/grit_rule.gni")
 
 assert(is_chromeos, "Non-ChromeOS builds cannot depend on //chromeos")
@@ -20,7 +21,10 @@ grit("resources") {
   ]
   output_dir = "$root_gen_dir/chromeos"
 
-  defines = [ "enable_cros_libassistant=$enable_cros_libassistant" ]
+  defines = [
+    "enable_cros_libassistant=$enable_cros_libassistant",
+    "enable_cros_media_app=$enable_cros_media_app",
+  ]
 
   grit_flags = [
     "-E",

chromeos/resources/chromeos_resources.grd

@@ -18,6 +18,7 @@
       <if expr="enable_cros_libassistant">
         <part file="assistant_resources.grdp" />
       </if>
+      <part file="media_app_resources.grdp" />
     </includes>
   </release>
 </grit>

chromeos/resources/media_app_resources.grdp

+<?xml version="1.0" encoding="utf-8"?>
+<grit-part>
+  <include name="IDR_MEDIA_APP_INDEX_HTML"
+      file="../components/media_app_ui/resources/index.html"
+      type="BINDATA" />
+  <include name="IDR_MEDIA_APP_APP_HTML"
+      file="../components/media_app_ui/resources/app.html"
+      type="BINDATA" />
+  <if expr="enable_cros_media_app">
+    <then>
+      <include name="IDR_MEDIA_APP_APP_JS"
+          file="../components/media_app_ui/resources/app/js/app_main.js"
+          type="BINDATA" />
+      <include name="IDR_MEDIA_APP_IMAGE_HANDLER_MODULE_JS"
+          file="../components/media_app_ui/resources/app/js/app_image_handler_module.js"
+          type="BINDATA" />
+      <include name="IDR_MEDIA_APP_DROP_TARGET_MODULE_JS"
+          file="../components/media_app_ui/resources/app/js/app_drop_target_module.js"
+          type="BINDATA" />
+    </then>
+    <else>
+      <include name="IDR_MEDIA_APP_APP_JS"
+          file="../components/media_app_ui/resources/mock/js/app_main.js"
+          type="BINDATA" />
+      <include name="IDR_MEDIA_APP_IMAGE_HANDLER_MODULE_JS"
+          file="../components/media_app_ui/resources/mock/js/mock_module.js"
+          type="BINDATA" />
+      <include name="IDR_MEDIA_APP_DROP_TARGET_MODULE_JS"
+          file="../components/media_app_ui/resources/mock/js/mock_module.js"
+          type="BINDATA" />
+    </else>
+  </if>
+</grit-part>