AU: delta compress the kernel partition

src/platform/update_engine/test_utils.cc

Index: src/platform/update_engine/test_utils.cc
diff --git a/src/platform/update_engine/test_utils.cc b/src/platform/update_engine/test_utils.cc
index 851e45d9693cc729036cf526047d92a105a289bf..a075c2d930d19f7fa71590653d5d7c610b3e107c 100644
--- a/src/platform/update_engine/test_utils.cc
+++ b/src/platform/update_engine/test_utils.cc
@@ -35,15 +35,6 @@ bool WriteFileString(const std::string& path, const std::string& data) {
   return utils::WriteFile(path.c_str(), data.data(), data.size());
 }
 
-off_t FileSize(const string& path) {
-  struct stat stbuf;
-  int rc = stat(path.c_str(), &stbuf);
-  CHECK_EQ(rc, 0);
-  if (rc < 0)
-    return rc;
-  return stbuf.st_size;
-}
-
 std::string Readlink(const std::string& path) {
   vector<char> buf(PATH_MAX + 1);
   ssize_t r = readlink(path.c_str(), &buf[0], buf.size());