MD Downloads: fix search spinner when terms are the same

chrome/browser/resources/md_downloads/action_service_unittest.gtestjs

Index: chrome/browser/resources/md_downloads/action_service_unittest.gtestjs
diff --git a/chrome/browser/resources/md_downloads/action_service_unittest.gtestjs b/chrome/browser/resources/md_downloads/action_service_unittest.gtestjs
index 9f850352f75ac9b204fad8f69be043897aefc448..d7670bd870ea4bd36fbd74f66f6ff430e086dd5d 100644
--- a/chrome/browser/resources/md_downloads/action_service_unittest.gtestjs
+++ b/chrome/browser/resources/md_downloads/action_service_unittest.gtestjs
@@ -37,3 +37,23 @@ TEST_F('ActionServiceUnitTest', 'splitTerms', function() {
   assertEquals(str(['a', 'b b', 'c']),
                str(ActionService.splitTerms('a "b b" c')));
 });
+
+TEST_F('ActionServiceUnitTest', 'searchWithSimilarTerms', function() {
+  /**
+   * @extends {downloads.ActionService}
+   * @constructor
+   */
+  function TestActionService() {
+    downloads.ActionService.call(this);
+  }
+
+  TestActionService.prototype = {
+    __proto__: downloads.ActionService.prototype,
+    loadMore: function() { /* No chrome.send() for you! */ },
+  };
+
+  var actionService = new TestActionService();
+
+  assertTrue(actionService.search('a'));
+  assertFalse(actionService.search('a '));  // Same term + space should no-op.
+});