Don’t use using directives (“using namespace”) in tools

tools/exception_port_tool.cc

Index: tools/exception_port_tool.cc
diff --git a/tools/exception_port_tool.cc b/tools/exception_port_tool.cc
index 52ef223b2705454aa9ab6e40a1dc87049969cbf0..a3996d89429a448dbb8a6d526c818580f67a7ac8 100644
--- a/tools/exception_port_tool.cc
+++ b/tools/exception_port_tool.cc
@@ -35,10 +35,9 @@
 #include "util/mach/symbolic_constants_mach.h"
 #include "util/stdlib/string_number_conversion.h"
 
+namespace crashpad {
 namespace {
 
-using namespace crashpad;
-
 //! \brief Manages a pool of Mach send rights, deallocating all send rights upon
 //!     destruction.
 //!
@@ -348,9 +347,7 @@ void Usage(const std::string& me) {
   ToolSupport::UsageTail(me);
 }
 
-}  // namespace
-
-int main(int argc, char* argv[]) {
+int ExceptionPortToolMain(int argc, char* argv[]) {
   const std::string me(basename(argv[0]));
 
   enum ExitCode {
@@ -587,3 +584,10 @@ int main(int argc, char* argv[]) {
 
   return kExitSuccess;
 }
+
+}  // namespace
+}  // namespace crashpad
+
+int main(int argc, char* argv[]) {
+  return crashpad::ExceptionPortToolMain(argc, argv);
+}