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

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

Index: chrome/test/data/extensions/api_test/file_system/test_util.js
diff --git a/chrome/test/data/extensions/api_test/file_system/test_util.js b/chrome/test/data/extensions/api_test/file_system/test_util.js
index ecefc00ace8eab4080f8cb5546223a855b77bc26..a768b029fbdfbdd14813c457d1bb741f3f5993ca 100644
--- a/chrome/test/data/extensions/api_test/file_system/test_util.js
+++ b/chrome/test/data/extensions/api_test/file_system/test_util.js
@@ -9,7 +9,7 @@ function checkEntry(entry, expectedName, isNew, shouldBeWritable) {
   chrome.test.assertEq(expectedName, entry.name);
 
   // Test that we are writable (or not), as expected.
-  chrome.fileSystem.isWritableFileEntry(entry, chrome.test.callbackPass(
+  chrome.fileSystem.isWritableEntry(entry, chrome.test.callbackPass(
       function(isWritable) {
     chrome.test.assertEq(isWritable, shouldBeWritable);
   }));
@@ -36,7 +36,7 @@ function checkEntry(entry, expectedName, isNew, shouldBeWritable) {
           } else {
             if (shouldBeWritable) {
               // Get a new entry and check the data got to disk.
-              chrome.fileSystem.chooseFile(chrome.test.callbackPass(
+              chrome.fileSystem.chooseEntry(chrome.test.callbackPass(
                   function(readEntry) {
                 readEntry.file(chrome.test.callback(function(readFile) {
                   var readReader = new FileReader();