Do not merge.

Check for a null tab in onDestroy. This fix is in master but the crash appears
in donut as well.
diff --git a/src/com/android/browser/BrowserActivity.java b/src/com/android/browser/BrowserActivity.java
index e9ce8d5..f9c4dc9 100644
--- a/src/com/android/browser/BrowserActivity.java
+++ b/src/com/android/browser/BrowserActivity.java
@@ -1195,8 +1195,10 @@
         super.onDestroy();
         // Remove the current tab and sub window
         TabControl.Tab t = mTabControl.getCurrentTab();
-        dismissSubWindow(t);
-        removeTabFromContentView(t);
+        if (t != null) {
+            dismissSubWindow(t);
+            removeTabFromContentView(t);
+        }
         // Destroy all the tabs
         mTabControl.destroy();
         WebIconDatabase.getInstance().close();