Replace FilePath with base::FilePath in some more top level directories.

rlz/test/rlz_test_helpers.cc

Index: rlz/test/rlz_test_helpers.cc
diff --git a/rlz/test/rlz_test_helpers.cc b/rlz/test/rlz_test_helpers.cc
index 32719e0a24bcfe4dfe31ce1b122902fabc4fbe73..398d0da5c88660f40f3f5b3615bfdb36d7d70e20 100644
--- a/rlz/test/rlz_test_helpers.cc
+++ b/rlz/test/rlz_test_helpers.cc
@@ -75,7 +75,7 @@ void RlzLibTestNoMachineState::TearDown() {
 #if defined(OS_WIN)
   UndoOverrideRegistryHives();
 #elif defined(OS_POSIX)
-  rlz_lib::testing::SetRlzStoreDirectory(FilePath());
+  rlz_lib::testing::SetRlzStoreDirectory(base::FilePath());
 #endif  // defined(OS_WIN)
 }