Update from https://crrev.com/304418

base/test/multiprocess_test_android.cc

 // Copyright (c) 2012 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/posix/global_descriptors.h"
 #include "base/test/multiprocess_test.h"
 
 #include <unistd.h>
 
+#include "base/base_switches.h"
+#include "base/command_line.h"
 #include "base/containers/hash_tables.h"
 #include "base/logging.h"
+#include "base/posix/global_descriptors.h"
 #include "testing/multiprocess_func_list.h"
 
 namespace base {
 
 // A very basic implementation for Android. On Android tests can run in an APK
 // and we don't have an executable to exec*. This implementation does the bare
 // minimum to execute the method specified by procname (in the child process).
-//  - |base_command_line| is ignored.
 //  - All options except |fds_to_remap| are ignored.
 ProcessHandle SpawnMultiProcessTestChild(const std::string& procname,
                                          const CommandLine& base_command_line,
                                          const LaunchOptions& options) {
   // TODO(viettrungluu): The FD-remapping done below is wrong in the presence of
   // cycles (e.g., fd1 -> fd2, fd2 -> fd1). crbug.com/326576
   FileHandleMappingVector empty;
   const FileHandleMappingVector* fds_to_remap =
       options.fds_to_remap ? options.fds_to_remap : &empty;
 
@@ skipping 23 matching lines @@
   }
   for (FileHandleMappingVector::const_iterator it = fds_to_remap->begin();
        it != fds_to_remap->end(); ++it) {
     int old_fd = it->first;
     int new_fd = it->second;
     if (dup2(old_fd, new_fd) < 0) {
       PLOG(FATAL) << "dup2";
     }
     close(old_fd);
   }
+  CommandLine::Reset();
+  CommandLine::Init(0, nullptr);
+  CommandLine* command_line = CommandLine::ForCurrentProcess();
+  command_line->InitFromArgv(base_command_line.argv());
+  if (!command_line->HasSwitch(switches::kTestChildProcess))
+    command_line->AppendSwitchASCII(switches::kTestChildProcess, procname);
+
   _exit(multi_process_function_list::InvokeChildProcessTest(procname));
   return 0;
 }
 
 }  // namespace base