Add support for deferring app initialization when testing.

This will allow certain app features such as authentication and loading of the
host list to be replaced with mocks before they are used; in normal operation,
these features are run automatically when the app is loaded, giving browser
tests no opportunity to intervene.

This is achieved by using the "source" URL parameter. Production code is
unaffected by virtue of the fact that "source" is not passed by default, and
even if a user is running with a command-line override, it will never be set
to "test". As protection against the possibility that the previous sentence
is false, when started in this test mode, initialization proceeds via a
button click, making it user-accessible; this CL also adds a test that this
button works.

Review URL: https://codereview.chromium.org/771003002

Cr-Commit-Position: refs/heads/master@{#308513}

chrome/test/remoting/auth_browsertest.cc

@@ -11,7 +11,7 @@ IN_PROC_BROWSER_TEST_F(RemoteDesktopBrowserTest, MANUAL_Auth) {
 
   Install();
 
-  LaunchChromotingApp();
+  LaunchChromotingApp(false);
 
   // Authorize, Authenticate, and Approve.
   Auth();

chrome/test/remoting/launch_browsertest.cc

@@ -11,7 +11,18 @@ IN_PROC_BROWSER_TEST_F(RemoteDesktopBrowserTest, MANUAL_Launch) {
 
   Install();
 
-  LaunchChromotingApp();
+  LaunchChromotingApp(false);
+
+  Cleanup();
+}
+
+IN_PROC_BROWSER_TEST_F(RemoteDesktopBrowserTest, MANUAL_LaunchDeferredStart) {
+  VerifyInternetAccess();
+
+  Install();
+
+  LaunchChromotingApp(true);
+  StartChromotingApp();
 
   Cleanup();
 }

chrome/test/remoting/me2me_browsertest.cc

@@ -36,7 +36,7 @@ IN_PROC_BROWSER_TEST_F(Me2MeBrowserTest,
                        MANUAL_Me2Me_Connect_Remote_Host) {
   VerifyInternetAccess();
   Install();
-  LaunchChromotingApp();
+  LaunchChromotingApp(false);
 
   // Authorize, Authenticate, and Approve.
   Auth();
@@ -110,7 +110,7 @@ void Me2MeBrowserTest::ConnectPinlessAndCleanupPairings(bool cleanup_all) {
   // TODO(jamiewalch): This reload is only needed because there's a bug in the
   // web-app whereby it doesn't refresh its pairing state correctly.
   // http://crbug.com/311290
-  LaunchChromotingApp();
+  LaunchChromotingApp(false);
   ASSERT_TRUE(HtmlElementVisible("paired-client-manager-message"));
 
   // Second connection: verify that no PIN is requested.

chrome/test/remoting/page_load_notification_observer.cc

@@ -15,15 +15,24 @@ PageLoadNotificationObserver::PageLoadNotificationObserver(const GURL& target)
           content::NOTIFICATION_LOAD_STOP,
           base::Bind(&PageLoadNotificationObserver::IsTargetLoaded,
                      base::Unretained(this))),
-      target_(target) {
+      target_(target),
+      ignore_url_parameters_(false) {
 }
 
 PageLoadNotificationObserver::~PageLoadNotificationObserver() {}
 
 bool PageLoadNotificationObserver::IsTargetLoaded() {
   content::NavigationController* controller =
       content::Source<content::NavigationController>(source()).ptr();
-  return controller->GetWebContents()->GetURL() == target_;
+  GURL current_url =  controller->GetWebContents()->GetURL();
+  if (ignore_url_parameters_) {
+    GURL::Replacements strip_query;
+    strip_query.ClearQuery();
+    return current_url.ReplaceComponents(strip_query) ==
+        target_.ReplaceComponents(strip_query);
+  } else {
+    return current_url == target_;
+  }
 }
 
 }  // namespace remoting

chrome/test/remoting/page_load_notification_observer.h

@@ -23,9 +23,16 @@ class PageLoadNotificationObserver
 
   ~PageLoadNotificationObserver() override;
 
+  void set_ignore_url_parameters(bool ignore_url_parameters) {
+    ignore_url_parameters_ = ignore_url_parameters;
+  }
+
  private:
   bool IsTargetLoaded();
+
   GURL target_;
+  bool ignore_url_parameters_;
+
   DISALLOW_COPY_AND_ASSIGN(PageLoadNotificationObserver);
 };
 

chrome/test/remoting/remote_desktop_browsertest.cc

@@ -166,14 +166,22 @@ void RemoteDesktopBrowserTest::VerifyChromotingLoaded(bool expected) {
   ASSERT_EQ(installed, expected);
 }
 
-void RemoteDesktopBrowserTest::LaunchChromotingApp() {
+void RemoteDesktopBrowserTest::LaunchChromotingApp(bool defer_start) {
   ASSERT_TRUE(extension_);
 
   GURL chromoting_main = Chromoting_Main_URL();
   // We cannot simply wait for any page load because the first page
   // loaded could be the generated background page. We need to wait
   // till the chromoting main page is loaded.
   PageLoadNotificationObserver observer(chromoting_main);
+  observer.set_ignore_url_parameters(true);
+
+  // If the app should be started in deferred mode, ensure that a "source" URL
+  // parameter; if not, ensure that no such parameter is present. The value of
+  // the parameter is determined by the AppLaunchParams ("test", in this case).
+  extensions::FeatureSwitch::ScopedOverride override_trace_app_source(
+      extensions::FeatureSwitch::trace_app_source(),
+      defer_start);
 
   OpenApplication(AppLaunchParams(browser()->profile(), extension_,
                                   is_platform_app()
@@ -210,6 +218,10 @@ void RemoteDesktopBrowserTest::LaunchChromotingApp() {
   EXPECT_EQ(Chromoting_Main_URL(), GetCurrentURL());
 }
 
+void RemoteDesktopBrowserTest::StartChromotingApp() {
+  ClickOnControl("browser-test-continue-init");
+};
+
 void RemoteDesktopBrowserTest::Authorize() {
   // The chromoting extension should be installed.
   ASSERT_TRUE(extension_);
@@ -465,7 +477,7 @@ void RemoteDesktopBrowserTest::Cleanup() {
 void RemoteDesktopBrowserTest::SetUpTestForMe2Me() {
   VerifyInternetAccess();
   Install();
-  LaunchChromotingApp();
+  LaunchChromotingApp(false);
   Auth();
   LoadScript(app_web_content(), FILE_PATH_LITERAL("browser_test.js"));
   ExpandMe2Me();

chrome/test/remoting/remote_desktop_browsertest.h

@@ -86,8 +86,16 @@ class RemoteDesktopBrowserTest : public extensions::PlatformAppBrowserTest {
   // Test whether the chromoting extension is installed.
   void VerifyChromotingLoaded(bool expected);
 
-  // Launch the chromoting app.
-  void LaunchChromotingApp();
+  // Launch the Chromoting app. If |defer_start| is true, an additional URL
+  // parameter is passed to the application, causing it to defer start-up
+  // until StartChromotingApp is invoked. Test code can execute arbitrary
+  // JavaScript in the context of the app between these two calls, for example
+  // to set up appropriate mocks.
+  void LaunchChromotingApp(bool defer_start);
+
+  // If the Chromoting app was launched in deferred mode, tell it to continue
+  // its regular start-up sequence.
+  void StartChromotingApp();
 
   // Authorize: grant extended access permission to the user's computer.
   void Authorize();
@@ -223,19 +231,16 @@ class RemoteDesktopBrowserTest : public extensions::PlatformAppBrowserTest {
 
   // Helper to construct the starting URL of the installed chromoting webapp.
   GURL Chromoting_Main_URL() {
-    if (is_platform_app())
-      // The v2 remoting app recently (M38 at the latest) started adding a
-      // query-string parameter to the main extension page. So we'll create a
-      // different expected URL for it.
-      return GURL("chrome-extension://" + ChromotingID() +
-        "/main.html?isKioskSession=false");
-    else
-      return GURL("chrome-extension://" + ChromotingID() + "/main.html");
+    return GURL("chrome-extension://" + ChromotingID() + "/main.html");
   }
 
-  // Helper to retrieve the current URL in the active WebContents.
+  // Helper to retrieve the current URL in the active WebContents. This function
+  // strips all query parameters from the URL.
   GURL GetCurrentURL() {
-    return active_web_contents()->GetURL();
+    GURL current_url = active_web_contents()->GetURL();
+    GURL::Replacements strip_query;
+    strip_query.ClearQuery();
+    return current_url.ReplaceComponents(strip_query);
   }
 
   // Helpers to execute JavaScript code on a web page.

remoting/webapp/crd/html/template_main.html

@@ -33,6 +33,15 @@
            hidden, but are shown appropriately when the mode changes. -->
       <section id="loading-mode" data-ui-mode="">
         <em>Loading&hellip;</em>
+        <div id="browser-test-deferred-init" hidden>
+        <p>
+          Running in test mode. If you are seeing this message in any other
+          context, please <a href="http://crbug.com" target="_blank">file a
+          bug</a>.
+        </p>
+        <p>
+          <button id="browser-test-continue-init">Continue</button>
+        </p>
       </section>
 
       <div id="daemon-plugin-container"></div>

remoting/webapp/crd/js/crd_main.js

@@ -177,12 +177,31 @@ remoting.updateLocalHostState = function() {
 };
 
 /**
- * Entry point ('load' handler) for Remote Desktop (CRD) webapp.
+ * Entry point for test code. In order to make test and production
+ * code as similar as possible, the same entry point is used for
+ * production code, but since production code should never have
+ * 'source' set to 'test', it continue with initialization
+ * immediately. As a fail-safe, the mechanism by which initialization
+ * completes when under test is controlled by a simple UI, making it
+ * possible to use the app even if the previous assumption fails to
+ * hold in some corner cases.
  */
+remoting.initDesktopRemotingForTesting = function() {
+  var urlParams = getUrlParameters_();
+  if (urlParams['source'] === 'test') {
+    document.getElementById('browser-test-continue-init').addEventListener(
+        'click', remoting.initDesktopRemoting, false);
+    document.getElementById('browser-test-deferred-init').hidden = false;
+  } else {
+    remoting.initDesktopRemoting();
+  }
+}
+
+
 remoting.initDesktopRemoting = function() {
   remoting.app = new remoting.Application();
   var desktop_remoting = new remoting.DesktopRemoting(remoting.app);
   remoting.app.init();
 };
 
-window.addEventListener('load', remoting.initDesktopRemoting, false);
+window.addEventListener('load', remoting.initDesktopRemotingForTesting, false);