[fsp] Add support for opening 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 7a80d5b6c07e8ac313e86eefe36ab75c87b92391..294d09af9a0f838c9129e137c4eacb52cb5fd265 100644
--- a/chrome/common/extensions/api/file_system_provider_internal.idl
+++ b/chrome/common/extensions/api/file_system_provider_internal.idl
@@ -48,6 +48,19 @@ namespace fileSystemProviderInternal {
         long fileSystemId,
         long requestId,
         fileSystemProvider.ProviderError error);
+
+    // Internal. Success callback of the <code>onOpenFileRequested</code> event.
+    // Must be called, when opening succeeds.
+    static void openFileRequestedSuccess(
+        long fileSystemId,
+        long requestId);
+
+    // Internal. Error callback of the <code>onOpenFileRequested</code> event.
+    // Must be called when opening fails.
+    static void openFileRequestedError(
+        long fileSystemId,
+        long requestId,
+        fileSystemProvider.ProviderError error);
   };
 };