Fixes a crash when entering a negative index with chrome.tabs.move ....

chrome/test/data/extensions/api_test/tabs/basics/move.html

Index: chrome/test/data/extensions/api_test/tabs/basics/move.html
===================================================================
--- chrome/test/data/extensions/api_test/tabs/basics/move.html	(revision 65777)
+++ chrome/test/data/extensions/api_test/tabs/basics/move.html	(working copy)
@@ -69,6 +69,25 @@
         }));
       }));
     }));
+
+    // Check that the browser doesn't segfault on a negative index
+    // or an out of range integer (BUG=53990).
+    chrome.tabs.getAllInWindow(firstWindowId, pass(function(tabs) {
+      lastTab = tabs.pop()
+      try {
+        chrome.tabs.move(lastTab.id, {'windowId': firstWindowId, 'index': -1});
+      }
+      catch(err) { 
+        // Always generates an exception, but it doesn't need to be handled
+        // because it's tested in js_schema_test.js.
+      }
+      try {
+        chrome.tabs.move(lastTab.id,{'index':1E10});
+      }
+      catch(err) {
+        // Also doesn't need to be handled.
+      }
+    }));
   },
 
   function remove() {