base: Remove using declaration from test_suite.h header.

chrome/installer/util/run_all_unittests.cc

Index: chrome/installer/util/run_all_unittests.cc
diff --git a/chrome/installer/util/run_all_unittests.cc b/chrome/installer/util/run_all_unittests.cc
index 3e1f5e41842f8a761a4eebd7c3037e4756042f9c..fb1b1d7a07293ba4327f9a703e9f9be09dba4c45 100644
--- a/chrome/installer/util/run_all_unittests.cc
+++ b/chrome/installer/util/run_all_unittests.cc
@@ -9,7 +9,7 @@
 #include "chrome/common/chrome_paths.h"
 
 int main(int argc, char** argv) {
-  TestSuite test_suite(argc, argv);
+  base::TestSuite test_suite(argc, argv);
 
   // Register Chrome Path provider so that we can get test data dir.
   chrome::RegisterPathProvider();