Handle error condition when inserting snapshots

 Bug: 5599226

Change-Id: I4429ed965325d908cdc5094c37d856f4d9d68933
diff --git a/src/com/android/browser/Controller.java b/src/com/android/browser/Controller.java
index 9710669..9402a77 100644
--- a/src/com/android/browser/Controller.java
+++ b/src/com/android/browser/Controller.java
@@ -1624,12 +1624,20 @@
                         @Override
                         protected Long doInBackground(Tab... params) {
                             Uri result = cr.insert(Snapshots.CONTENT_URI, values);
+                            if (result == null) {
+                                return null;
+                            }
                             long id = ContentUris.parseId(result);
                             return id;
                         }
 
                         @Override
                         protected void onPostExecute(Long id) {
+                            if (id == null) {
+                                Toast.makeText(mActivity, R.string.snapshot_failed,
+                                        Toast.LENGTH_SHORT).show();
+                                return;
+                            }
                             Bundle b = new Bundle();
                             b.putLong(BrowserSnapshotPage.EXTRA_ANIMATE_ID, id);
                             mUi.showComboView(ComboViews.Snapshots, b);