Move MediaGalleries.getMediaFileSystems back to experimental for M22

chrome/common/extensions/api/experimental_media_galleries.idl

Index: chrome/common/extensions/api/experimental_media_galleries.idl
diff --git a/chrome/common/extensions/api/experimental_media_galleries.idl b/chrome/common/extensions/api/experimental_media_galleries.idl
index e9d51e6b2fba14a13e625629c717484f49d3c7b4..ab8b04eb32b4a9ac87b59099bd875b0da0292674 100644
--- a/chrome/common/extensions/api/experimental_media_galleries.idl
+++ b/chrome/common/extensions/api/experimental_media_galleries.idl
@@ -6,10 +6,37 @@
 
 namespace experimental.mediaGalleries {
 
+  [inline_doc] enum GetMediaFileSystemsInteractivity {
+    // Do not act interactively.
+    no,
+    // Ask the user to manage permitted media galleries.
+    yes,
+    // Ask the user to manage permitted galleries only if the return set would
+    // otherwise be empty.
+    if_needed
+  };
+
+  [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;
+  };
+
+  callback MediaFileSystemsCallback =
+      void ([instanceOf=LocalFileSystem] optional object[] mediaFileSystems);
+
   callback AssembleMediaFileCallback =
       void ([instanceOf=Blob] optional object mediaFile);
 
   interface Functions {
+    // Get the media galleries configured in this user agent. If none are
+    // configured or available, the callback will receive an empty array.
+    static void getMediaFileSystems(optional MediaFileSystemsDetails details,
+                                    MediaFileSystemsCallback callback);
+
     // Create a new MediaFile setting the metadata in the Blob to the supplied
     // values, overriding any existing metadata in the media file. If user agent
     // does not recognize the Blob as a supported file format, it will fail.