[fsp] Add a method to enumerate all mounted file systems.

chrome/common/extensions/api/file_system_provider.idl

 // Copyright 2013 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.fileSystemProvider</code> API to create file systems,
 // that can be accessible from the file manager on Chrome OS.
 [platforms=("chromeos"),
  implemented_in="chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h"]
 namespace fileSystemProvider {
   // Error codes used by providing extensions in response to requests. For
@@ skipping 35 matching lines @@
     // File size in bytes.
     double size;
 
     // The last modified time of this entry.
     [instanceOf=Date] object modificationTime;
 
     // Mime type for the entry.
     DOMString? mimeType; 
   };
 
+  // Represents a mounted file system.
+  dictionary FileSystemInfo {
+    DOMString fileSystemId;
+    DOMString displayName;
+    [nodoc] boolean writable;
+  };
+
   // Options for the <code>mount()</code> method.
   dictionary MountOptions {
     DOMString fileSystemId;
     DOMString displayName;
     [nodoc] boolean? writable;
   };
 
   // Options for the <code>unmount()</code> method.
   dictionary UnmountOptions {
     DOMString fileSystemId;
@@ skipping 100 matching lines @@
     double length;
     ArrayBuffer data;
   };
 
   // Callback to receive the result of mount() function.
   callback MountCallback = void([nodoc, instanceOf=DOMError] object error);
 
   // Callback to receive the result of unmount() function.
   callback UnmountCallback = void([nodoc, instanceOf=DOMError] object error);
 
+  // Callback to receive the result of getAll() function.
+  callback GetAllCallback = void(FileSystemInfo[] fileSystems);
+
   // Callback to handle an error raised from the browser.
   [nocompile] callback ErrorCallback = void([instanceOf=DOMError] object error);
 
   // Callback to be called by the providing extension in case of a success.
   callback ProviderSuccessCallback = void();
 
   // Callback to be called by the providing extension in case of an error.
   callback ProviderErrorCallback = void(ProviderError error);
 
   // Success callback for the <code>onGetMetadataRequested</code> event.
@@ skipping 29 matching lines @@
 
     // Unmounts a file system with the given <code>fileSystemId</code>. It
     // should be called after <code>onUnmountRequested</code> is invoked. Also,
     // the providing extension can decide to perform unmounting if not requested
     // (eg. in case of lost connection, or a file error). If there is no file
     // system with the requested id, or unmounting fails, then the
     // <code>errorCallback</code> will be called.
     static void unmount(UnmountOptions options,
                         UnmountCallback successCallback,
                         [nocompile] ErrorCallback errorCallback);
+
+    // Returns all file systems mounted by the extension.
+    static void getAll(GetAllCallback callback);
   };
 
   interface Events {
     // Raised when unmounting for the file system with the <code>fileSystemId
     // </code> identifier is requested. In the response, the <code>unmount
     // </code> API method should be called together with <code>successCallback
     // </code>. If unmounting is not possible (eg. due to a pending operation),
     // then <code>errorCallback</code> must be called.
     [maxListeners=1] static void onUnmountRequested(
         UnmountRequestedOptions options,
@@ skipping 89 matching lines @@
 
     // Raised when writing contents to a file opened previously with <code>
     // openRequestId</code> is requested.
     [maxListeners=1, nodoc] static void onWriteFileRequested(
         WriteFileRequestedOptions options,
         ProviderSuccessCallback successCallback,
         ProviderErrorCallback errorCallback);
   };
 };