Fix downstream Chrome OS build.

Bug: None
Test: FEATURES=test emerge-link update_engine

Change-Id: I4550ede90c92a86c74b7e5aa96e6df58230ed3d8
diff --git a/common/utils_unittest.cc b/common/utils_unittest.cc
index eaae023..634de01 100644
--- a/common/utils_unittest.cc
+++ b/common/utils_unittest.cc
@@ -443,11 +443,11 @@
   EXPECT_TRUE(BoolMacroTestHelper());
 }
 
-TEST(UtilsTest, UnmountFilesystemFailureTest) {
+TEST(UtilsTest, RunAsRootUnmountFilesystemFailureTest) {
   EXPECT_FALSE(utils::UnmountFilesystem("/path/to/non-existing-dir"));
 }
 
-TEST(UtilsTest, UnmountFilesystemBusyFailureTest) {
+TEST(UtilsTest, RunAsRootUnmountFilesystemBusyFailureTest) {
   string tmp_image;
   EXPECT_TRUE(utils::MakeTempFile("img.XXXXXX", &tmp_image, nullptr));
   ScopedPathUnlinker tmp_image_unlinker(tmp_image);