[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..ce84d699db4aa3a39650bae88dd75f84a48a30e8 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
@@ -7,10 +7,12 @@ package org.chromium.chrome.browser.signin;
 import android.app.Activity;
 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.PrefServiceBridge;
 import org.chromium.sync.signin.ChromeSigninController;
+import org.chromium.ui.base.WindowAndroid;
 
 /**
 * Helper functions for promoting sign in.
@@ -41,4 +43,18 @@ public class SigninPromoUtil {
         preferenceManager.setSigninPromoShown();
         return true;
     }
+
+    /**
+     * A convenience method to create an AccountSigninActivity, passing the access point as an
+     * intent extra.
+     * @param window WindowAndroid from which to get the Activity/Context.
+     * @param accessPoint for metrics purposes.
+     */
+    @CalledByNative
+    private static void openAccountSigninActivityForPromo(WindowAndroid window, int accessPoint) {
+        Activity activity = window.getActivity().get();
+        if (activity != null) {
+            AccountSigninActivity.startIfAllowed(activity, accessPoint);
+        }
+    }
 }