Media Galleries API Scanning: Add Scan Permission and basic test.

chrome/common/extensions/api/media_galleries.idl

 // Copyright (c) 2012 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 the <code>chrome.mediaGalleries</code> API to access media files (images,
 // video, audio) from the user's local disks (with the user's consent).
 namespace mediaGalleries {
 
   [inline_doc] enum GetMediaFileSystemsInteractivity {
     // Do not act interactively.
@@ skipping 12 matching lines @@
     mimeTypeOnly
   };
 
   [inline_doc] enum ScanProgressType {
     // The scan started.
     start,
     // The scan was cancelled.
     cancel,
     // The scan finished but none of the result have been added,
     // addScanResults() has to be called to ask the user for permission.
-    finish
+    finish,
+    // The scan had an error and could not proceed.

[Lei Zhang, 2014/01/29 23:07:53]

nit: s/had/encountered/ ?

[tommycli, 2014/01/29 23:19:56]

Done.

+    error
   };
 
   [inline_doc] dictionary MediaFileSystemsDetails {
     // Whether to prompt the user for permission to additional media galleries
     // before returning the permitted set. Default is silent.  If the value
     // 'yes' is passed, or if the application has not been granted access to
     // any media galleries and the value 'if_needed' is passed, then the
     // media gallery configuration dialog will be displayed.
     GetMediaFileSystemsInteractivity? interactive;
   };
@@ skipping 118 matching lines @@
                             optional MediaMetadataOptions options,
                             MediaMetadataCallback callback);
   };
 
   interface Events {
     // The pending media scan has changed state. See details for more
     // information.
     static void onScanProgress(ScanProgressDetails details);
   };
 };