Fix examples for File System Provider API.

chrome/common/extensions/docs/examples/api/fileSystemProvider/basic/background.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 // Fake data similar to a file system structure.
 var MODIFICATION_DATE = new Date();
 var SHORT_CONTENTS = 'Just another example.';
 var LONGER_CONTENTS = 'It works!\nEverything gets displayed correctly.';
 
 var METADATA = {
-  '/': {isDirectory: true, name: '/', size: 0,
+  '/': {isDirectory: true, name: '', size: 0,
       modificationTime: MODIFICATION_DATE},
   '/file1.txt': {isDirectory: false, name: 'file1.txt',
       size: LONGER_CONTENTS.length, modificationTime: MODIFICATION_DATE,
       contents: LONGER_CONTENTS},
   '/file2': {isDirectory: false, name: 'file2', size: 150,
       modificationTime: MODIFICATION_DATE},
   '/dir': {isDirectory: true, name: 'dir', size: 0,
       modificationTime: MODIFICATION_DATE},
   '/dir/file3.txt': {isDirectory: false, name: 'file3.txt',
       size: SHORT_CONTENTS.length, modificationTime: MODIFICATION_DATE,
@@ skipping 68 matching lines @@
   // Write the contents as ASCII text.
   var buffer = new ArrayBuffer(options.length);
   var bufferView = new Uint8Array(buffer);
   for (var i = 0; i < options.length; i++) {
     bufferView[i] = contents.charCodeAt(i);
   }
 
   onSuccess(buffer, false /* Last call. */);
 }
 
-// Mount the file system.
-chrome.runtime.onInstalled.addListener(function(details) {
+function onMountRequested(onSuccess, onError) {
   chrome.fileSystemProvider.mount(
       {fileSystemId: 'sample-file-system', displayName: 'Sample File System'},
-      function() {},
-      function() { console.error('Failed to mount.'); });
-});
+      function() {
+        if (chrome.runtime.lastError) {
+          onError(chrome.runtime.lastError.message);
+          console.error('Failed to mount because of: ' +
+              chrome.runtime.lastError.message);
+          return;
+        }
+        onSuccess();
+      });
+}
+
+function onUnmountRequested(options, onSuccess, onError) {
+  chrome.fileSystemProvider.unmount(
+      {fileSystemId: options.fileSystemId},
+      function() {
+        if (chrome.runtime.lastError) {
+          onError(chrome.runtime.lastError.message);
+          console.error('Failed to unmount because of: ' +
+              chrome.runtime.lastError.message);
+          return;
+        }
+        onSuccess();
+      });
+}
 
 chrome.fileSystemProvider.onGetMetadataRequested.addListener(
     onGetMetadataRequested);
 chrome.fileSystemProvider.onReadDirectoryRequested.addListener(
     onReadDirectoryRequested);
-chrome.fileSystemProvider.onOpenFileRequested.addListener(
-    onOpenFileRequested);
+chrome.fileSystemProvider.onOpenFileRequested.addListener(onOpenFileRequested);
 chrome.fileSystemProvider.onCloseFileRequested.addListener(
     onCloseFileRequested);
-chrome.fileSystemProvider.onReadFileRequested.addListener(
-    onReadFileRequested);
+chrome.fileSystemProvider.onReadFileRequested.addListener(onReadFileRequested);
+chrome.fileSystemProvider.onMountRequested.addListener(onMountRequested);
+chrome.fileSystemProvider.onUnmountRequested.addListener(onUnmountRequested);