[Autofill] Add support for signin promo on Android

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

Index: chrome/android/java/src/org/chromium/chrome/browser/signin/SigninPromoUtil.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/signin/SigninPromoUtil.java b/chrome/android/java/src/org/chromium/chrome/browser/signin/SigninPromoUtil.java
index 34b66fcc4ec94666db7d9b6f0257f670ccfe2581..01bfe96fea4612b27e95340ae0dffc3b1234e320 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/signin/SigninPromoUtil.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/signin/SigninPromoUtil.java
@@ -5,10 +5,13 @@
 package org.chromium.chrome.browser.signin;
 
 import android.app.Activity;
+import android.content.Context;
 import android.text.TextUtils;
 
+import org.chromium.base.annotations.CalledByNative;
 import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
 import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
+import org.chromium.chrome.browser.preferences.ManagedPreferencesUtils;
 import org.chromium.chrome.browser.preferences.PrefServiceBridge;
 import org.chromium.sync.signin.ChromeSigninController;
 
@@ -37,8 +40,28 @@ public class SigninPromoUtil {
             return false;
         }
 
-        AccountSigninActivity.startAccountSigninActivity(activity, SigninAccessPoint.SIGNIN_PROMO);
+        AccountSigninActivity.startAccountSigninActivity(
+                activity, SigninAccessPoint.SIGNIN_PROMO, /* useNewTaskFlag */ false);
         preferenceManager.setSigninPromoShown();
         return true;
     }
+
+    /**
+     * A convenience method to create an AccountSigninActivity on a new task, passing the access
+     * point as an intent extra.
+     * @param accessPoint for metrics purposes.
+     */
+    @CalledByNative
+    public static void openAccountSigninActivityForPromo(Context context, int accessPoint) {
+        if (!SigninManager.get(context).isSignInAllowed()) {
+            if (SigninManager.get(context).isSigninDisabledByPolicy()) {
+                ManagedPreferencesUtils.showManagedByAdministratorToast(context);
+            }
+            return;
+        }
+
+        AccountSigninActivity.startAccountSigninActivity(
+                context, accessPoint, /* useNewTaskFlag */ true);
+        return;
+    }
 }