[cros] RLZ tracking can be turned off via a flag file.

rlz/test/rlz_unittest_main.cc

Index: rlz/test/rlz_unittest_main.cc
diff --git a/rlz/test/rlz_unittest_main.cc b/rlz/test/rlz_unittest_main.cc
index 8ebbaf88aeb8d7017ea204afa7be871151b96c85..f2e99cb1e6743aa7ac73d55ec18be71f9a6675a0 100644
--- a/rlz/test/rlz_unittest_main.cc
+++ b/rlz/test/rlz_unittest_main.cc
@@ -10,6 +10,12 @@
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(OS_POSIX)
+#include "base/file_path.h"
+#include "base/files/scoped_temp_dir.h"
+#include "rlz/lib/rlz_value_store.h"
+#endif
+
 int main(int argc, char **argv) {
   base::AtExitManager at_exit;
   CommandLine::Init(argc, argv);
@@ -21,6 +27,13 @@ int main(int argc, char **argv) {
   if (ret == 0) {
     // Now re-run all the tests using a supplementary brand code.  This brand
     // code will remain in effect for the lifetime of the branding object.
+#if defined(OS_POSIX)
+    // Set a temporary directory for RLZ here, because SupplementaryBranding
+    // creates and owns RlzValueStore object for its lifetime.
+    base::ScopedTempDir temp_dir;
+    if (temp_dir.CreateUniqueTempDir())
+      rlz_lib::testing::SetRlzStoreDirectory(temp_dir.path());
+#endif
     rlz_lib::SupplementaryBranding branding("TEST");
     ret = RUN_ALL_TESTS();
   }