diff --git a/aosp/update_attempter_android_unittest.cc b/aosp/update_attempter_android_unittest.cc
index 81a3230..d67bf01 100644
--- a/aosp/update_attempter_android_unittest.cc
+++ b/aosp/update_attempter_android_unittest.cc
@@ -63,6 +63,11 @@
 
 namespace chromeos_update_engine {
 
+// Compare the value of builtin array for download source parameter.
+MATCHER_P(DownloadSourceMatcher, source_array, "") {
+  return std::equal(source_array, source_array + kNumDownloadSources, arg);
+}
+
 class UpdateAttempterAndroidTest : public ::testing::Test {
  protected:
   UpdateAttempterAndroidTest() = default;
@@ -97,6 +102,8 @@
   testing::NiceMock<MockMetricsReporter>* metrics_reporter_;
 };
 
+namespace {
+
 TEST_F(UpdateAttempterAndroidTest, UpdatePrefsSameBuildVersionOnInit) {
   std::string build_version =
       android::base::GetProperty("ro.build.version.incremental", "");
@@ -208,18 +215,10 @@
 
   int64_t total_bytes[kNumDownloadSources] = {};
   total_bytes[kDownloadSourceHttpsServer] = 90;
-  EXPECT_CALL(*metrics_reporter_,
-              ReportSuccessfulUpdateMetrics(
-                  _,
-                  _,
-                  _,
-                  50,
-                  test_utils::DownloadSourceMatcher(total_bytes),
-                  80,
-                  _,
-                  _,
-                  _,
-                  _))
+  EXPECT_CALL(
+      *metrics_reporter_,
+      ReportSuccessfulUpdateMetrics(
+          _, _, _, 50, DownloadSourceMatcher(total_bytes), 80, _, _, _, _))
       .Times(1);
 
   // Adds a payload of 50 bytes to the InstallPlan.
@@ -249,4 +248,6 @@
       0, metrics_utils::GetPersistedValue(kPrefsTotalBytesDownloaded, &prefs_));
 }
 
+}  // namespace
+
 }  // namespace chromeos_update_engine