Now mBookmarksAdapter is created asynchronously,
we need to check null before using it.

Fix http://b/issue?id=2610515
diff --git a/src/com/android/browser/BrowserBookmarksPage.java b/src/com/android/browser/BrowserBookmarksPage.java
index a824a84..7560c78 100644
--- a/src/com/android/browser/BrowserBookmarksPage.java
+++ b/src/com/android/browser/BrowserBookmarksPage.java
@@ -679,6 +679,7 @@
      *  Refresh the shown list after the database has changed.
      */
     private void refreshList() {
+        if (mBookmarksAdapter == null) return;
         mBookmarksAdapter.refreshList();
     }