diff --git a/utils.h b/utils.h
index 2374a94..6d8b373 100644
--- a/utils.h
+++ b/utils.h
@@ -28,6 +28,7 @@
 #include "update_engine/constants.h"
 #include "update_engine/file_descriptor.h"
 #include "update_engine/metrics.h"
+#include "update_engine/update_metadata.pb.h"
 
 namespace chromeos_update_engine {
 
@@ -468,6 +469,14 @@
 // value and setting it, and |false| otherwise.
 bool GetMinorVersion(base::FilePath path, uint32_t* minor_version);
 
+// This function reads the specified data in |extents| into |out_data|. The
+// extents are read from the file at |path|. |out_data_size| is the size of
+// |out_data|. Returns false if the number of bytes to read given in
+// |extents| does not equal |out_data_size|.
+bool ReadExtents(const std::string& path, std::vector<Extent>* extents,
+                 chromeos::Blob* out_data, ssize_t out_data_size,
+                 size_t block_size);
+
 }  // namespace utils