[Smart Lock] Auto sign-in snackbar UI.

chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
index d5fd63346e1597589cc0e89bbf605b967abd85b5..ed165645ca401459afd9032d0a373248e210bc77 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
@@ -2239,6 +2239,14 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
     }
 
     /**
+     * Called when a showing auto sign-in UI is requested by credential manager API.
+     */
+    @CalledByNative
+    private void onSmartLockAutoSignIn(Object credential) {
+        for (TabObserver observer : mObservers) observer.onSmartLockAutoSignIn(credential);
+    }
+
+    /**
      * @return The native pointer representing the native side of this {@link Tab} object.
      */
     @CalledByNative