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/ActiveTabsPage.java b/src/com/android/browser/ActiveTabsPage.java
index 52d943f..0feba9a 100644
--- a/src/com/android/browser/ActiveTabsPage.java
+++ b/src/com/android/browser/ActiveTabsPage.java
@@ -83,7 +83,8 @@
     @Override
     public void onItemClick(
             AdapterView<?> parent, View view, int position, long id) {
-        boolean needToAttach = !mController.switchToTab(position);
+        final Tab tab = mTabControl.getTab(position);
+        boolean needToAttach = !mController.switchToTab(tab);
         mController.removeActiveTabsPage(needToAttach);
     }