Browser: fix force close when remove a history

The delete item id in bookmarks page, history page
and snapshot page is the same, when tap delete item
in history page, the event was handled by snapshot
page, then an exception happened.

If current context menu doesn't belong to current
page, let other fragment deal with it.

CRs-Fixed: 538142

Change-Id: Id9ebb1a4717bea3e4e30d6491089f8a1bd6fdaee
diff --git a/src/com/android/browser/BrowserSnapshotPage.java b/src/com/android/browser/BrowserSnapshotPage.java
index b0d8205..0d36c48 100644
--- a/src/com/android/browser/BrowserSnapshotPage.java
+++ b/src/com/android/browser/BrowserSnapshotPage.java
@@ -182,6 +182,9 @@
 
     @Override
     public boolean onContextItemSelected(MenuItem item) {
+        if (!(item.getMenuInfo() instanceof AdapterContextMenuInfo)) {
+            return false;
+        }
         if (item.getItemId() == R.id.delete_context_menu_id) {
             AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
             deleteSnapshot(info.id);