Remove uses of WaitForExitCode

tools/gn/exec_process.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/process/kill.h"
 #include "base/process/launch.h"
+#include "base/process/process.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 
 #include "base/win/scoped_handle.h"
 #include "base/win/scoped_process_information.h"
 #endif
 
 #if defined(OS_POSIX)
 #include <fcntl.h>
@@ skipping 208 matching lines @@
               HANDLE_EINTR(select(std::max(out_read.get(), err_read.get()) + 1,
                                   &read_fds, nullptr, nullptr, nullptr));
           if (res <= 0)
             break;
           if (FD_ISSET(out_read.get(), &read_fds))
             out_open = ReadFromPipe(out_read.get(), std_out);
           if (FD_ISSET(err_read.get(), &read_fds))
             err_open = ReadFromPipe(err_read.get(), std_err);
         }
 
-        return base::WaitForExitCode(pid, exit_code);
+        base::Process process(pid);
+        return process.WaitForExit(exit_code);
       }
   }
 
   return false;
 }
 #endif
 
 }  // namespace internal