[fsp] Add support for closing files.

chrome/common/extensions/api/file_system_provider_internal.idl

Index: chrome/common/extensions/api/file_system_provider_internal.idl
diff --git a/chrome/common/extensions/api/file_system_provider_internal.idl b/chrome/common/extensions/api/file_system_provider_internal.idl
index 294d09af9a0f838c9129e137c4eacb52cb5fd265..582bc7dd79a13b9cf7ecefeef7908bea74230bcb 100644
--- a/chrome/common/extensions/api/file_system_provider_internal.idl
+++ b/chrome/common/extensions/api/file_system_provider_internal.idl
@@ -61,6 +61,19 @@ namespace fileSystemProviderInternal {
         long fileSystemId,
         long requestId,
         fileSystemProvider.ProviderError error);
+
+    // Internal. Success callback of the <code>onCloseFileRequested</code>
+    // event. Must be called, when closing succeeds.
+    static void closeFileRequestedSuccess(
+        long fileSystemId,
+        long requestId);
+
+    // Internal. Error callback of the <code>onCloseFileRequested</code> event.
+    // Must be called when closing fails.
+    static void closeFileRequestedError(
+        long fileSystemId,
+        long requestId,
+        fileSystemProvider.ProviderError error);
   };
 };