Add multiplexing of message pipes in the new EDK.

mojo/edk/system/data_pipe_unittest.cc

Index: mojo/edk/system/data_pipe_unittest.cc
diff --git a/mojo/edk/system/data_pipe_unittest.cc b/mojo/edk/system/data_pipe_unittest.cc
index 5c8f0f84eb74e923bb26b61defabb4ba09f57aff..0880f60845eeba77ecd66ed8ccad3e31f67e1f80 100644
--- a/mojo/edk/system/data_pipe_unittest.cc
+++ b/mojo/edk/system/data_pipe_unittest.cc
@@ -32,7 +32,7 @@ const uint32_t kSizeOfOptions =
 // TODO(vtl): Get rid of this.
 const size_t kMaxPoll = 100;
 
-class DataPipeTest : public test::MojoSystemTest {
+class DataPipeTest : public testing::Test {
  public:
   DataPipeTest() : producer_(MOJO_HANDLE_INVALID),
                    consumer_(MOJO_HANDLE_INVALID) {}