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

util/mac/mac_util_test.mm

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 16 matching lines @@
 // When C++ exceptions are disabled, libstdc++ from GCC 4.2 defines |try| and
 // |catch| so as to allow exception-expecting C++ code to build properly when
 // language support for exceptions is not present. These macros interfere with
 // the use of |@try| and |@catch| in Objective-C files such as this one.
 // Undefine these macros here, after everything has been #included, since there
 // will be no C++ uses and only Objective-C uses from this point on.
 #undef try
 #undef catch
 #endif
 
+namespace crashpad {
+namespace test {
 namespace {
 
-using namespace crashpad;
-
 // Runs /usr/bin/sw_vers with a single argument, |argument|, and places the
 // command’s standard output into |output| after stripping the trailing newline.
 // Fatal gtest assertions report tool failures, which the caller should check
 // for with testing::Test::HasFatalFailure().
 void SwVers(NSString* argument, std::string* output) {
   @autoreleasepool {
     base::scoped_nsobject<NSPipe> pipe([[NSPipe alloc] init]);
     base::scoped_nsobject<NSTask> task([[NSTask alloc] init]);
     [task setStandardOutput:pipe];
     [task setLaunchPath:@"/usr/bin/sw_vers"];
@@ skipping 89 matching lines @@
   // MacModelAndBoard() gets the data, so it wouldn’t be a very useful test.
   std::string model;
   std::string board;
   MacModelAndBoard(&model, &board);
 
   EXPECT_FALSE(model.empty());
   EXPECT_FALSE(board.empty());
 }
 
 }  // namespace
+}  // namespace test
+}  // namespace crashpad