Declare providing extension capabilities in the manifest.

chrome/common/extensions/api/file_manager_private.idl

Index: chrome/common/extensions/api/file_manager_private.idl
diff --git a/chrome/common/extensions/api/file_manager_private.idl b/chrome/common/extensions/api/file_manager_private.idl
index 230fab885fa352b71ae503c0af5299ef98921854..d06febffdd7939a967999a1dc9fa12a28c91b781 100644
--- a/chrome/common/extensions/api/file_manager_private.idl
+++ b/chrome/common/extensions/api/file_manager_private.idl
@@ -173,19 +173,9 @@ enum EntryTagVisibility {
   public
 };
 
-// Source of the volume data.
-enum VolumeSource {
-  // Represents a mounted file. In most cases, simply an archive.
-  file,
-
-  // Representing a device, eg. an MTP device. Also, used for Downloads as it's
-  // containing files stored on the Chrome OS device.
-  device,
-
-  // Used for volumes which contain files on a remote machine, eg. Drive or
-  // cloud services implemented via the File System Provider API.
-  network
-};
+// Source of provided file system's data. See Provided File System API docs for
+// details.
+enum Source { file, device, network };

[not at google - send to devlin, 2015/04/23 23:16:35]

When https://codereview.chromium.org/1100333006/ goes in you'll be able to
directly reference the other file and not need to declare this enum at all,
i.e., below where you have:

// Source of file systems' data.
Source source;

you should be able to have:

// Source of the file system's data.
fileSystemProvider.Source source;

[mtomasz, 2015/04/24 12:16:10]

Done.

 
 // A file task represents an action that the file manager can perform over the
 // currently selected files. See
@@ -300,9 +290,6 @@ dictionary VolumeMetadata {
   // Extension providing this volume (for provided file systems).
   DOMString? extensionId;
 
-  // Source of the volume data.
-  VolumeSource? volumeSource;
-
   // Label of the volume (if available).
   DOMString? volumeLabel;
 
@@ -527,10 +514,13 @@ dictionary ProvidingExtension {
   DOMString name;
 
   // Whether supports configuration dialog.
-  boolean canConfigure;
+  boolean configurable;
+
+  // Whether supports mounting multiple instances.
+  boolean multipleMounts;
 
-  // Whether supports adding new instances.
-  boolean canAdd;
+  // Source of file systems' data.
+  Source source;
 };
 
 // Callback that does not take arguments.