Update from https://crrev.com/304121

base/test/launcher/unit_test_launcher.cc

 // Copyright 2013 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/test/launcher/unit_test_launcher.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 461 matching lines @@
     fflush(stdout);
   } else {
     if (base::debug::BeingDebugged()) {
       fprintf(stdout,
               "Debugger detected, switching to single process mode.\n"
               "Pass --test-launcher-debug-launcher to debug the launcher "
               "itself.\n");
       fflush(stdout);
       force_single_process = true;
     }
-
-    if (RunningOnValgrind()) {
-      fprintf(stdout,
-              "Valgrind detected, switching to single process mode.\n"
-              "Pass --test-launcher-debug-launcher to valgrind the launcher "
-              "itself.\n");
-      fflush(stdout);
-      force_single_process = true;
-    }
   }
 
   if (CommandLine::ForCurrentProcess()->HasSwitch(kGTestHelpFlag) ||
       CommandLine::ForCurrentProcess()->HasSwitch(kGTestListTestsFlag) ||
       CommandLine::ForCurrentProcess()->HasSwitch(kSingleProcessTestsFlag) ||
       force_single_process) {
     return run_test_suite.Run();
   }
 #endif
 
@@ skipping 75 matching lines @@
   CommandLine::Init(argc, NULL);
   return LaunchUnitTestsInternal(
       run_test_suite,
       SysInfo::NumberOfProcessors(),
       use_job_objects,
       Bind(&InitGoogleTestWChar, &argc, argv));
 }
 #endif  // defined(OS_WIN)
 
 }  // namespace base