Mark DOMStringList.contains() as deprecated, add console warning.

LayoutTests/storage/indexeddb/mozilla/resources/indexes.js

 // original test:
 // http://mxr.mozilla.org/mozilla2.0/source/dom/indexedDB/test/test_indexes.html?force=1
 // license of original test:
 // " Any copyright is dedicated to the Public Domain.
 //   http://creativecommons.org/publicdomain/zero/1.0/ "
 
 if (this.importScripts) {
     importScripts('../../../../resources/js-test.js');
     importScripts('../../resources/shared.js');
 }
@@ skipping 75 matching lines @@
 
 function setVersionComplete()
 {
     objectStore = evalAndLog("objectStore = db.transaction(objectStoreName).objectStore(objectStoreName);");
 
     // Check global properties to make sure they are correct.
     shouldBe("objectStore.indexNames.length", "indexData.length");
     for (i in indexData) {
         found = false;
         for (j = 0; j < objectStore.indexNames.length; j++) {
-            if (objectStore.indexNames.item(j) == indexData[i].name) {
+            if (objectStore.indexNames[j] == indexData[i].name) {
                 found = true;
                 break;
             }
         }
         shouldBeTrue("found");
         index = evalAndLog("index = objectStore.index(indexData[i].name);");
         shouldBe("index.name", "indexData[i].name");
         shouldBe("index.keyPath", "indexData[i].keyPath");
         shouldBe("index.unique", indexData[i].options.unique ? "true" : "false");
     }
@@ skipping 865 matching lines @@
             }
 
             keyIndex += keyIndex ? 1 : 2;
         }
         else {
             shouldBe("keyIndex", "objectStoreDataNameSort.length");
             finishJSTest();
         }
     }
 }