AU: move AU completed marker from /tmp to /var/run since /var/run is root-only.

BUG=6578
TEST=unit tests, gmerged on device, updated, restarted update engine and
checked status

Change-Id: If703b66f1bf6efa13f25225d3c5868bc3dd190b7

Review URL: http://codereview.chromium.org/3404015
diff --git a/update_attempter_unittest.cc b/update_attempter_unittest.cc
index 0a02d1c..ed58572 100644
--- a/update_attempter_unittest.cc
+++ b/update_attempter_unittest.cc
@@ -20,7 +20,7 @@
 namespace chromeos_update_engine {
 
 // Test a subclass rather than the main class directly so that we can mock out
-// methods within the class. There're explicit unit test for the mocked out
+// methods within the class. There're explicit unit tests for the mocked out
 // methods.
 class UpdateAttempterUnderTest : public UpdateAttempter {
  public:
@@ -52,7 +52,7 @@
   ActionProcessorMock* processor_;
 };
 
-TEST_F(UpdateAttempterTest, ConstructWithUpdatedMarkerTest) {
+TEST_F(UpdateAttempterTest, RunAsRootConstructWithUpdatedMarkerTest) {
   extern const char* kUpdateCompletedMarker;
   const FilePath kMarker(kUpdateCompletedMarker);
   EXPECT_EQ(0, file_util::WriteFile(kMarker, "", 0));