AU: Try delta updates first, then full updates

src/platform/update_engine/utils_unittest.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <errno.h>
+#include <string>
 #include <vector>
 #include <gtest/gtest.h>
 #include "update_engine/utils.h"
 
+using std::string;
 using std::vector;
 
 namespace chromeos_update_engine {
 
 class UtilsTest : public ::testing::Test { };
 
 TEST(UtilsTest, NormalizePathTest) {
   EXPECT_EQ("", utils::NormalizePath("", false));
   EXPECT_EQ("", utils::NormalizePath("", true));
   EXPECT_EQ("/", utils::NormalizePath("/", false));
@@ skipping 81 matching lines @@
 
 TEST(UtilsTest, TempFilenameTest) {
   const string original = "/foo.XXXXXX";
   const string result = utils::TempFilename(original);
   EXPECT_EQ(original.size(), result.size());
   EXPECT_TRUE(utils::StringHasPrefix(result, "/foo."));
   EXPECT_FALSE(utils::StringHasSuffix(result, "XXXXXX"));
 }
 
 }  // namespace chromeos_update_engine