Rename chrome.fileSystem apis to be expandable to directories if we wish.

chrome/test/data/extensions/api_test/file_system/save_new/test.js

Index: chrome/test/data/extensions/api_test/file_system/save_new/test.js
diff --git a/chrome/test/data/extensions/api_test/file_system/save_new/test.js b/chrome/test/data/extensions/api_test/file_system/save_new/test.js
index f9f2b48adbe903586a1ece8e1a8ca6fdd6d94d59..b6e633d2a6cfc3342e55340b6de1596728abdebc 100644
--- a/chrome/test/data/extensions/api_test/file_system/save_new/test.js
+++ b/chrome/test/data/extensions/api_test/file_system/save_new/test.js
@@ -4,7 +4,7 @@
 
 chrome.test.runTests([
   function saveFile() {
-    chrome.fileSystem.chooseFile({type: 'saveFile'}, chrome.test.callbackFail(
+    chrome.fileSystem.chooseEntry({type: 'saveFile'}, chrome.test.callbackFail(
         'Operation requires fileSystemWrite permission',  function() {}));
   }
 ]);