introduce tab IDs

    Tabs are identified by IDs now, instead of their position
    Refactored the save/restore code

Change-Id: I7133d55831201d097dc19ec938a85e7085f36749
diff --git a/src/com/android/browser/UrlHandler.java b/src/com/android/browser/UrlHandler.java
index c76eee8..02a080f 100644
--- a/src/com/android/browser/UrlHandler.java
+++ b/src/com/android/browser/UrlHandler.java
@@ -258,7 +258,7 @@
 
         protected void onPostExecute(String result) {
             // Make sure the Tab was not closed while handling the task
-            if (mController.getTabControl().getTabIndex(mTab) != -1) {
+            if (mController.getTabControl().getTabPosition(mTab) != -1) {
                 // If the Activity Manager is not invoked, load the URL directly
                 if (!startActivityForUrl(result)) {
                     if (!handleMenuClick(mTab, result)) {