AU: FilesystemCopierAction: copy bit-exactly

src/platform/update_engine/utils.cc

Index: src/platform/update_engine/utils.cc
diff --git a/src/platform/update_engine/utils.cc b/src/platform/update_engine/utils.cc
index 7f05ffbcfa9e22e664d17bdac21ce7ff167b4ea7..724a4ba81e0733319340ff818f0a42bfcfd56e81 100644
--- a/src/platform/update_engine/utils.cc
+++ b/src/platform/update_engine/utils.cc
@@ -333,6 +333,12 @@ bool UnmountFilesystem(const string& mountpoint) {
   return true;
 }
 
+const char* GetGErrorMessage(const GError* error) {
+  if (!error)
+    return "Unknown error.";
+  return error->message;
+}
+
 const char* const kStatefulPartition = "/mnt/stateful_partition";
 
 }  // namespace utils