Mojo: (POSIX) Pass channel handle to child.

mojo/common/test/multiprocess_test_base_unittest.cc

Index: mojo/common/test/multiprocess_test_base_unittest.cc
diff --git a/mojo/common/test/multiprocess_test_base_unittest.cc b/mojo/common/test/multiprocess_test_base_unittest.cc
index 681d8bc453bb5055d6fef384f24c28a4efe8bee6..9609d1b479405e9ee3a7fb3c6408884db713dcd9 100644
--- a/mojo/common/test/multiprocess_test_base_unittest.cc
+++ b/mojo/common/test/multiprocess_test_base_unittest.cc
@@ -4,6 +4,10 @@
 
 #include "mojo/common/test/multiprocess_test_base.h"
 
+#include "base/logging.h"
+// TODO(vtl): Remove build_config.h include when fully implemented on Windows.
+#include "build/build_config.h"
+
 namespace mojo {
 namespace {
 
@@ -16,6 +20,12 @@ TEST_F(MultiprocessTestBaseTest, RunChild) {
 }
 
 MOJO_MULTIPROCESS_TEST_CHILD_MAIN(RunChild) {
+// TODO(vtl): Not implemented on Windows yet.
+#if defined(OS_POSIX)
+  CHECK(MultiprocessTestBaseTest::platform_client_channel.get());
+  CHECK(MultiprocessTestBaseTest::platform_client_channel->is_valid());
+  // TODO(vtl): Check the client channel.
+#endif
   return 123;
 }