Don't schedule periodic update checks for non-official builds.

BUG=5334
TEST=unit tests, gmerged on device and tried with different tracks

Review URL: http://codereview.chromium.org/3041044
diff --git a/utils_unittest.cc b/utils_unittest.cc
index a66e739..b67114a 100644
--- a/utils_unittest.cc
+++ b/utils_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -17,6 +17,11 @@
 
 class UtilsTest : public ::testing::Test { };
 
+TEST(UtilsTest, IsOfficialBuild) {
+  // Pretty lame test...
+  EXPECT_TRUE(utils::IsOfficialBuild());
+}
+
 TEST(UtilsTest, NormalizePathTest) {
   EXPECT_EQ("", utils::NormalizePath("", false));
   EXPECT_EQ("", utils::NormalizePath("", true));