Add support for persistent file access in apps.

chrome/test/data/extensions/api_test/file_system/retain_entry/test_other_window.js

Index: chrome/test/data/extensions/api_test/file_system/retain_entry/test_other_window.js
diff --git a/chrome/test/data/extensions/api_test/file_system/get_entry_id/test_other_window.js b/chrome/test/data/extensions/api_test/file_system/retain_entry/test_other_window.js
similarity index 56%
rename from chrome/test/data/extensions/api_test/file_system/get_entry_id/test_other_window.js
rename to chrome/test/data/extensions/api_test/file_system/retain_entry/test_other_window.js
index 875a10e5810f4c1a349240de48f86f873d158b81..4ea34513e23af3180d0f1d5aa6523a9c8039a4b5 100644
--- a/chrome/test/data/extensions/api_test/file_system/get_entry_id/test_other_window.js
+++ b/chrome/test/data/extensions/api_test/file_system/retain_entry/test_other_window.js
@@ -6,10 +6,16 @@ chrome.runtime.getBackgroundPage(
     chrome.test.callbackPass(function(backgroundPage) {
   chrome.fileSystem.chooseEntry({type: 'openFile'},
       chrome.test.callbackPass(function(entry) {
-    var id = chrome.fileSystem.getEntryId(entry);
+    var id = chrome.fileSystem.retainEntry(entry);
     chrome.test.assertTrue(id != null);
-    var e = chrome.fileSystem.getEntryById(id);
-    chrome.test.assertEq(e, entry);
+    chrome.fileSystem.isRestorable(id, chrome.test.callbackPass(
+        function(isRestorable) {
+      chrome.test.assertTrue(isRestorable);
+    }));
+    chrome.fileSystem.restoreEntry(id, chrome.test.callbackPass(
+        function(restoredEntry) {
+      chrome.test.assertEq(restoredEntry, entry);
+    }));
     backgroundPage.callback(window, id, entry);
   }));
 }));