Fix the new First Run sentinel file path determination.

chrome/browser/first_run/first_run_unittest.cc

Index: chrome/browser/first_run/first_run_unittest.cc
diff --git a/chrome/browser/first_run/first_run_unittest.cc b/chrome/browser/first_run/first_run_unittest.cc
index bccc9e82ceb6817596c4a88a0539fcc70b9c690f..c5e0c70a149b418e02466ef5befd55015da9bf30 100644
--- a/chrome/browser/first_run/first_run_unittest.cc
+++ b/chrome/browser/first_run/first_run_unittest.cc
@@ -21,12 +21,6 @@ class FirstRunTest : public testing::Test {
   FirstRunTest() : user_data_dir_override_(chrome::DIR_USER_DATA) {}
   virtual ~FirstRunTest() {}
 
-  virtual void SetUp() OVERRIDE {
-    internal::GetFirstRunSentinelFilePath(&sentinel_path_);
-  }
-
-  base::FilePath sentinel_path_;
-
  private:
   base::ScopedPathOverride user_data_dir_override_;
 
@@ -34,11 +28,14 @@ class FirstRunTest : public testing::Test {
 };
 
 TEST_F(FirstRunTest, RemoveSentinel) {
+  base::FilePath sentinel_path;
+  EXPECT_TRUE(internal::GetFirstRunSentinelFilePath(&sentinel_path));
+
   EXPECT_TRUE(internal::CreateSentinel());
-  EXPECT_TRUE(base::PathExists(sentinel_path_));
+  EXPECT_TRUE(base::PathExists(sentinel_path));
 
   EXPECT_TRUE(RemoveSentinel());
-  EXPECT_FALSE(base::PathExists(sentinel_path_));
+  EXPECT_FALSE(base::PathExists(sentinel_path));
 }
 
 TEST_F(FirstRunTest, SetupMasterPrefsFromInstallPrefs_VariationsSeed) {