[Signin][Android] Redirect to the continue_url in web sign-in

This CL redirects the web sign-in flow to the continue_url from Gaia
once the sign-in is finished.

Bug: 1092399
Change-Id: Ie51cfdab614c5c414abb2dee40759803c8d29491
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2264557Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Commit-Queue: Alice Wang <aliceywang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#782972}

chrome/android/java/src/org/chromium/chrome/browser/signin/SigninUtils.java

@@ -71,14 +71,15 @@ public class SigninUtils {
     }
 
     @CalledByNative
-    private static void openAccountPickerBottomSheet(WindowAndroid windowAndroid) {
+    private static void openAccountPickerBottomSheet(
+            WindowAndroid windowAndroid, String continueUrl) {
         ThreadUtils.assertOnUiThread();
         if (IdentityServicesProvider.get().getSigninManager().isSignInAllowed()) {
             ChromeActivity activity = (ChromeActivity) windowAndroid.getActivity().get();
             AccountPickerBottomSheetCoordinator coordinator =
                     new AccountPickerBottomSheetCoordinator(activity,
                             activity.getBottomSheetController(),
-                            new AccountPickerDelegate(activity));
+                            new AccountPickerDelegate(activity, continueUrl));
         }
     }
 

chrome/android/java/src/org/chromium/chrome/browser/signin/account_picker/AccountPickerDelegate.java

@@ -30,11 +30,13 @@ import org.chromium.content_public.browser.UiThreadTaskTraits;
 public class AccountPickerDelegate implements AccountPickerCoordinator.Listener {
     private final ChromeActivity mChromeActivity;
     private final Tab mTab;
+    private final String mContinueUrl;
 
-    public AccountPickerDelegate(ChromeActivity chromeActivity) {
+    public AccountPickerDelegate(ChromeActivity chromeActivity, String continueUrl) {
         mChromeActivity = chromeActivity;
         // TODO(https://crbug.com/1095554): Check if website redirects after sign-in
         mTab = mChromeActivity.getActivityTab();
+        mContinueUrl = continueUrl;
     }
     /**
      * Notifies that the user has selected an account.
@@ -54,11 +56,8 @@ public class AccountPickerDelegate implements AccountPickerCoordinator.Listener
                         // We should wait for the cookie signin and cookie regeneration here,
                         // PostTask.postDelayedTask is just a temporary measure for testing the
                         // flow, it will be removed soon.
-                        PostTask.postDelayedTask(UiThreadTaskTraits.DEFAULT, () -> {
-                            // TODO(https//crbug.com/1092399):
-                            // Replace this with a continue URL got from GAIA
-                            mTab.loadUrl(new LoadUrlParams("https://google.com"));
-                        }, 2000);
+                        PostTask.postDelayedTask(UiThreadTaskTraits.DEFAULT,
+                                () -> { mTab.loadUrl(new LoadUrlParams(mContinueUrl)); }, 2000);
                     }
 
                     @Override

chrome/browser/android/signin/signin_utils.cc

@@ -28,10 +28,14 @@ void SigninUtils::OpenAccountManagementScreen(
                     : base::android::ConvertUTF8ToJavaString(env, email));
 }
 
-void SigninUtils::OpenAccountPickerBottomSheet(ui::WindowAndroid* window) {
+void SigninUtils::OpenAccountPickerBottomSheet(
+    ui::WindowAndroid* window,
+    const std::string& continue_url) {
   DCHECK(window);
   JNIEnv* env = base::android::AttachCurrentThread();
-  Java_SigninUtils_openAccountPickerBottomSheet(env, window->GetJavaObject());
+  Java_SigninUtils_openAccountPickerBottomSheet(
+      env, window->GetJavaObject(),
+      base::android::ConvertUTF8ToJavaString(env, continue_url));
 }
 
 static void JNI_SigninUtils_LogEvent(JNIEnv* env,

chrome/browser/android/signin/signin_utils.h

@@ -23,7 +23,8 @@ class SigninUtils {
                                           const std::string& email);
 
   // Opens the account picker bottomsheet
-  static void OpenAccountPickerBottomSheet(ui::WindowAndroid* window);
+  static void OpenAccountPickerBottomSheet(ui::WindowAndroid* window,
+                                           const std::string& continue_url);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SigninUtils);

chrome/browser/signin/chrome_signin_helper.cc

@@ -297,7 +297,10 @@ void ProcessMirrorHeader(
   if (manage_accounts_params.show_consistency_promo &&
       base::FeatureList::IsEnabled(kMobileIdentityConsistency)) {
     auto* window = web_contents->GetNativeView()->GetWindowAndroid();
-    SigninUtils::OpenAccountPickerBottomSheet(window);
+    SigninUtils::OpenAccountPickerBottomSheet(
+        window, manage_accounts_params.continue_url.empty()
+                    ? chrome::kChromeUINativeNewTabURL
+                    : manage_accounts_params.continue_url);
     return;
   }
   if (service_type == signin::GAIA_SERVICE_TYPE_INCOGNITO) {