Support mojo connections between unrelated peer processes.

mojo/edk/test/mojo_test_base.h

Index: mojo/edk/test/mojo_test_base.h
diff --git a/mojo/edk/test/mojo_test_base.h b/mojo/edk/test/mojo_test_base.h
index 4f5514533a58de3112da5ab902686edb6a3bb90b..cd507daa81677dc07e9d3eb28ba3bfe5041de62d 100644
--- a/mojo/edk/test/mojo_test_base.h
+++ b/mojo/edk/test/mojo_test_base.h
@@ -29,6 +29,8 @@ class MojoTestBase : public testing::Test {
   MojoTestBase();
   ~MojoTestBase() override;
 
+  using LaunchType = MultiprocessTestHelper::LaunchType;
+
  protected:
   using HandlerCallback = base::Callback<void(ScopedMessagePipeHandle)>;
 
@@ -36,7 +38,8 @@ class MojoTestBase : public testing::Test {
    public:
     ClientController(const std::string& client_name,
                      MojoTestBase* test,
-                     const ProcessErrorCallback& process_error_callback_);
+                     const ProcessErrorCallback& process_error_callback,
+                     LaunchType launch_type);
     ~ClientController();
 
     MojoHandle pipe() const { return pipe_.get().value(); }
@@ -148,6 +151,8 @@ class MojoTestBase : public testing::Test {
   // Reads data from a data pipe.
   static std::string ReadData(MojoHandle consumer, size_t size);
 
+  void set_launch_type(LaunchType launch_type) { launch_type_ = launch_type; }
+
  private:
   friend class ClientController;
 
@@ -155,6 +160,8 @@ class MojoTestBase : public testing::Test {
 
   ProcessErrorCallback process_error_callback_;
 
+  LaunchType launch_type_ = LaunchType::CHILD;
+
   DISALLOW_COPY_AND_ASSIGN(MojoTestBase);
 };