Mojo: Add NotifyBadMessage API

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 3d5e56e3d1581fcd800a75320a9a212eded4ba99..94affc281b97691d5d3e7dc8d402d532a31a3aeb 100644
--- a/mojo/edk/test/mojo_test_base.h
+++ b/mojo/edk/test/mojo_test_base.h
@@ -34,13 +34,17 @@ class MojoTestBase : public testing::Test {
 
   class ClientController {
    public:
-    ClientController(const std::string& client_name, MojoTestBase* test);
+    ClientController(const std::string& client_name,
+                     MojoTestBase* test,
+                     const base::Closure& bad_message_callback);
     ~ClientController();
 
     MojoHandle pipe() const { return pipe_.get().value(); }
 
     int WaitForShutdown();
 
+    MultiprocessTestHelper& helper() { return helper_; }
+
    private:
     friend class MojoTestBase;
 
@@ -53,6 +57,13 @@ class MojoTestBase : public testing::Test {
     DISALLOW_COPY_AND_ASSIGN(ClientController);
   };
 
+  // Set the callback to handle bad messages received from test client
+  // processes. This can be set to a different callback before starting each
+  // client.
+  void set_bad_message_callback(const base::Closure& callback) {
+    bad_message_callback_ = callback;
+  }
+
   ClientController& StartClient(const std::string& client_name);
 
   template <typename HandlerFunc>
@@ -144,6 +155,8 @@ class MojoTestBase : public testing::Test {
 
   std::vector<std::unique_ptr<ClientController>> clients_;
 
+  base::Closure bad_message_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(MojoTestBase);
 };