Fix NPE in queryIsBookmark

 Bug: 3326838
 Fixed a case where a Tab can have a null URL and added null checks
 to the DataController.

Change-Id: I9b27479c522928cde5d427919f2f921ca94aec5d
diff --git a/src/com/android/browser/Tab.java b/src/com/android/browser/Tab.java
index c4edda6..320d3b3 100644
--- a/src/com/android/browser/Tab.java
+++ b/src/com/android/browser/Tab.java
@@ -546,6 +546,9 @@
             mInPageLoad = false;
             // Sync state (in case of stop/timeout)
             mCurrentState.mUrl = view.getUrl();
+            if (mCurrentState.mUrl == null) {
+                mCurrentState.mUrl = url != null ? url : "";
+            }
             mCurrentState.mTitle = view.getTitle();
             mCurrentState.mFavicon = view.getFavicon();
             if (!URLUtil.isHttpsUrl(mCurrentState.mUrl)) {