Files.app: Specify a test case name to the test system.

Previously the test system cannot obtain the name of test cases because they are
anonymous inline functions. And it causes a log like "[SUCCESS] undefined".

BUG=372683
TEST=run the tests

Review URL: https://codereview.chromium.org/288513002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270058 0039d316-1c4b-4281-b951-d872f2087c98

chrome/test/data/extensions/api_test/file_manager_browsertest/background.js

@@ -785,13 +785,14 @@ window.addEventListener('load', function() {
     },
     // Run the test case.
     function(testCaseName) {
-      if (!testcase[testCaseName]) {
-        chrome.test.runTests([function() {
-          chrome.test.fail(testCaseName + ' is not found.');
-        }]);
+      var targetTest = testcase[testCaseName];
+      if (!targetTest) {
+        chrome.test.fail(testCaseName + ' is not found.');
         return;
       }
-      chrome.test.runTests([testcase[testCaseName]]);
+      // Specify the name of test to the test system.
+      targetTest.generatedName = testCaseName;
+      chrome.test.runTests([targetTest]);
     }
   ];
   steps.shift()();