Revert of base: Remove using:: declaration from version.h header.

components/update_client/test_installer.cc

Index: components/update_client/test_installer.cc
diff --git a/components/update_client/test_installer.cc b/components/update_client/test_installer.cc
index 7a291994bc582c61717ad5473b7280d25463246f..ad6015b980083cba9386902bfad983e741bdbd14 100644
--- a/components/update_client/test_installer.cc
+++ b/components/update_client/test_installer.cc
@@ -62,7 +62,7 @@
                                      const base::FilePath& unpack_path) {
   std::string version_string;
   manifest.GetStringASCII("version", &version_string);
-  base::Version version(version_string);
+  Version version(version_string.c_str());
 
   base::FilePath path;
   path = install_directory_.AppendASCII(version.GetString());