Redirect USER_DATA_DIR for GoogleUpdateTest and FirstRunTest.

chrome/browser/first_run/first_run_unittest.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
 #include "base/file_util.h"
+#include "base/path_service.h"
+#include "base/scoped_temp_dir.h"
 #include "chrome/browser/first_run/first_run.h"
 #include "chrome/browser/first_run/first_run_internal.h"
+#include "chrome/common/chrome_paths.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class FirstRunTest : public testing::Test {
  protected:
-  virtual void SetUp() {
+  FirstRunTest() {}
+  virtual ~FirstRunTest() {}
+
+  virtual void SetUp() OVERRIDE {
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+    PathService::Override(chrome::DIR_USER_DATA, temp_dir_.path());
     first_run::internal::GetFirstRunSentinelFilePath(&sentinel_path_);
   }
 
   FilePath sentinel_path_;
+
+ private:
+  ScopedTempDir temp_dir_;
+
+  DISALLOW_COPY_AND_ASSIGN(FirstRunTest);
 };
 
 TEST_F(FirstRunTest, RemoveSentinel) {
   EXPECT_TRUE(first_run::CreateSentinel());
   EXPECT_TRUE(file_util::PathExists(sentinel_path_));
 
   EXPECT_TRUE(first_run::RemoveSentinel());
   EXPECT_FALSE(file_util::PathExists(sentinel_path_));
 }