Add multiplexing of message pipes in the new EDK.

mojo/edk/system/run_all_unittests.cc

Index: mojo/edk/system/run_all_unittests.cc
diff --git a/mojo/edk/system/run_all_unittests.cc b/mojo/edk/system/run_all_unittests.cc
index b68fd83e9d0e8d1b65c99615247490c2d783e500..4421aa69bc25944ac1f06c802c6fc8637693903a 100644
--- a/mojo/edk/system/run_all_unittests.cc
+++ b/mojo/edk/system/run_all_unittests.cc
@@ -5,9 +5,11 @@
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/test/launcher/unit_test_launcher.h"
+#include "base/test/test_io_thread.h"
 #include "base/test/test_suite.h"
 #include "mojo/edk/embedder/embedder.h"
 #include "mojo/edk/test/multiprocess_test_helper.h"
+#include "mojo/edk/test/scoped_ipc_support.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 int main(int argc, char** argv) {
@@ -31,6 +33,12 @@ int main(int argc, char** argv) {
 
   mojo::edk::Init();
 
+  base::TestIOThread test_io_thread(base::TestIOThread::kAutoStart);
+  // Leak this because its destructor calls mojo::edk::ShutdownIPCSupport which
+  // really does nothing in the new EDK but does depend on the current message
+  // loop, which is destructed inside base::LaunchUnitTests.
+  new mojo::edk::test::ScopedIPCSupport(test_io_thread.task_runner());
+
   return base::LaunchUnitTests(
       argc, argv,
       base::Bind(&base::TestSuite::Run, base::Unretained(&test_suite)));