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

tools/catch_exception_tool.cc

Index: tools/catch_exception_tool.cc
diff --git a/tools/catch_exception_tool.cc b/tools/catch_exception_tool.cc
index 10c23a455b56260f055e72d8ced9fc2af9ab7933..a6db7cebe2da2f3e661228fb57f9c369161f19ff 100644
--- a/tools/catch_exception_tool.cc
+++ b/tools/catch_exception_tool.cc
@@ -35,10 +35,9 @@
 #include "util/posix/symbolic_constants_posix.h"
 #include "util/stdlib/string_number_conversion.h"
 
+namespace crashpad {
 namespace {
 
-using namespace crashpad;
-
 struct Options {
   std::string file_path;
   std::string mach_service;
@@ -179,9 +178,7 @@ void Usage(const std::string& me) {
   ToolSupport::UsageTail(me);
 }
 
-}  // namespace
-
-int main(int argc, char* argv[]) {
+int CatchExceptionToolMain(int argc, char* argv[]) {
   const std::string me(basename(argv[0]));
 
   enum OptionFlags {
@@ -300,3 +297,10 @@ int main(int argc, char* argv[]) {
 
   return EXIT_SUCCESS;
 }
+
+}  // namespace
+}  // namespace crashpad
+
+int main(int argc, char* argv[]) {
+  return crashpad::CatchExceptionToolMain(argc, argv);
+}