[Android] Fix a bug that snackbar does not show when there is no tab on tablet

chrome/android/java/src/org/chromium/chrome/browser/snackbar/SnackbarManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/snackbar/SnackbarManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/snackbar/SnackbarManager.java b/chrome/android/java/src/org/chromium/chrome/browser/snackbar/SnackbarManager.java
index 2fbc62ec98c83403a6ee620a203ba0787ca155a3..b3918caa07966c0ed97921da1972464f192a748d 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/snackbar/SnackbarManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/snackbar/SnackbarManager.java
@@ -8,6 +8,7 @@ import android.app.Activity;
 import android.os.Handler;
 import android.view.View;
 import android.view.View.OnClickListener;
+import android.view.ViewGroup;
 
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.metrics.RecordHistogram;
@@ -146,6 +147,19 @@ public class SnackbarManager implements OnClickListener {
     }
 
     /**
+     * Temporarily changes the parent {@link ViewGroup} of the snackbar. If a snackbar is currently
+     * showing, this method removes the snackbar from its original parent, and attaches it to the
+     * given parent. If <code>null</code> is given, the snackbar will be reattached to its original
+     * parent.
+     *
+     * @param overridingParent The temporary parent of the snackbar. If null, previous calls of this
+     *                         method will be reverted.
+     */
+    public void overrideParent(ViewGroup overridingParent) {
+        if (mView != null) mView.overrideParent(overridingParent);
+    }
+
+    /**
      * @return Whether there is a snackbar on screen.
      */
     public boolean isShowing() {