AU: FilesystemCopierAction: copy bit-exactly

src/platform/update_engine/utils.h

Index: src/platform/update_engine/utils.h
diff --git a/src/platform/update_engine/utils.h b/src/platform/update_engine/utils.h
index bcbd8daae18b1c4db7e49712ba3f20ef959ced99..7b6fc102f199d9c4d63150e4a6d461e99819d412 100644
--- a/src/platform/update_engine/utils.h
+++ b/src/platform/update_engine/utils.h
@@ -10,6 +10,7 @@
 #include <set>
 #include <string>
 #include <vector>
+#include <glib.h>
 #include "update_engine/action.h"
 #include "update_engine/action_processor.h"
 
@@ -78,6 +79,9 @@ bool MountFilesystem(const std::string& device, const std::string& mountpoint,
                      unsigned long flags);
 bool UnmountFilesystem(const std::string& mountpoint);
 
+// Returns the error message, if any, from a GError pointer.
+const char* GetGErrorMessage(const GError* error);
+
 // Log a string in hex to LOG(INFO). Useful for debugging.
 void HexDumpArray(const unsigned char* const arr, const size_t length);
 inline void HexDumpString(const std::string& str) {