[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 b47019ca6d05e78bd242d7cb97f37db6b5822c03..c55575cffc88aa8b47e2debdb63c010fe855bcd1 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
@@ -54,6 +54,7 @@ import org.chromium.chrome.browser.metrics.UmaSessionStats;
 import org.chromium.chrome.browser.metrics.UmaUtils;
 import org.chromium.chrome.browser.printing.TabPrinter;
 import org.chromium.chrome.browser.profiles.Profile;
+import org.chromium.chrome.browser.snackbar.SnackbarManager;
 import org.chromium.chrome.browser.ssl.ConnectionSecurity;
 import org.chromium.chrome.browser.ssl.ConnectionSecurityLevel;
 import org.chromium.chrome.browser.tab.TabUma.TabCreationState;
@@ -2242,6 +2243,14 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
     }
 
     /**
+     * Returns the SnackbarManager for the activity that owns this Tab, if any. May
+     * return null.
+     */
+    public SnackbarManager getSnackbarManager() {
+        return null;
+    }
+
+    /**
      * @return The native pointer representing the native side of this {@link Tab} object.
      */
     @CalledByNative