Fix DCHECK in ipc_perftests

mojo/edk/test/multiprocess_test_helper.h

Index: mojo/edk/test/multiprocess_test_helper.h
diff --git a/mojo/edk/test/multiprocess_test_helper.h b/mojo/edk/test/multiprocess_test_helper.h
index c3b6e01c797a801d2824b2254da5cc51480280fe..6265acaefa42ba61a4d292c0e775daffcd239822 100644
--- a/mojo/edk/test/multiprocess_test_helper.h
+++ b/mojo/edk/test/multiprocess_test_helper.h
@@ -85,7 +85,8 @@ class MultiprocessTestHelper {
   // Used by macros in mojo/edk/test/mojo_test_base.h to support multiprocess
   // test client initialization.
   static void ChildSetup();
-  static int RunClientMain(const base::Callback<int(MojoHandle)>& main);
+  static int RunClientMain(const base::Callback<int(MojoHandle)>& main,
+                           bool close_pipe_on_exit = true);

[yzshen1, 2017/03/21 16:43:30]

nit: without reading the code, I am not sure who is responsible to close the
pipe, is it |main| or RunClientMain()? Does it make sense to change
|close_pipe_on_exit| to something like |passes_ownership_to_main|?

[Ken Rockot(use gerrit already), 2017/03/21 16:51:31]

Good point. I've changed it to pass_pipe_ownership_to_main and inverted the
usage.

   static int RunClientTestMain(const base::Callback<void(MojoHandle)>& main);
 
   // For use (and only valid) in the child process: