[fsp] Promote file system provider to stable.

chrome/common/extensions/api/file_system_provider_internal.idl

 // 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.
 
 // Internal, used by fileSystemProvider's custom bindings. These functions are
 // called when events' callbacks are invoked.
-[platforms=("chromeos"),
- implemented_in="chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h", nodoc]
+[implemented_in="chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h", nodoc]
 namespace fileSystemProviderInternal {
   interface Functions {
     // Internal. Success callback of the <code>onUnmountRequested</code>
     // event. Must be called when unmounting is completed.
     static void unmountRequestedSuccess(
         DOMString fileSystemId,
         long requestId,
         long executionTime);
 
     // Internal. Success callback of the <code>onGetMetadataRequested</code>
@@ skipping 32 matching lines @@
     // Internal. Error callback of all of the operation requests. Must be called
     // if an operation fails.
     static void operationRequestedError(
         DOMString fileSystemId,
         long requestId,
         fileSystemProvider.ProviderError error,
         long executionTime);
   };
 };