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/NavScreen.java b/src/com/android/browser/NavScreen.java
index 9f2d4ae..a5090fa 100644
--- a/src/com/android/browser/NavScreen.java
+++ b/src/com/android/browser/NavScreen.java
@@ -206,7 +206,7 @@
                     : R.drawable.ic_forward_disabled_holo_dark);
         }
         if (updateFlipper) {
-            mFlipper.setSelection(mUiController.getTabControl().getTabIndex(tab));
+            mFlipper.setSelection(mUiController.getTabControl().getTabPosition(tab));
         }
     }
 
@@ -249,7 +249,7 @@
 
         if (tab != null) {
             // set tab as the selected in flipper, then hide
-            final int tix = mUi.mTabControl.getTabIndex(tab);
+            final int tix = mUi.mTabControl.getTabPosition(tab);
             post(new Runnable() {
                 public void run() {
                     if (tix != -1) {