Mojo: Add NotifyBadMessage API

mojo/edk/embedder/embedder.h

Index: mojo/edk/embedder/embedder.h
diff --git a/mojo/edk/embedder/embedder.h b/mojo/edk/embedder/embedder.h
index 68c198b7067a1aa27eb914d12edc9abb6a34e72b..3a4747b799c61b46b897208bda5fd8610129ab46 100644
--- a/mojo/edk/embedder/embedder.h
+++ b/mojo/edk/embedder/embedder.h
@@ -29,6 +29,8 @@ namespace edk {
 
 class ProcessDelegate;
 
+using ProcessErrorCallback = base::Callback<void(const std::string& error)>;
+
 // Basic configuration/initialization ------------------------------------------
 
 // |Init()| sets up the basic Mojo system environment, making the |Mojo...()|
@@ -44,6 +46,16 @@ MOJO_SYSTEM_IMPL_EXPORT void ChildProcessLaunched(
     ScopedPlatformHandle server_pipe,
     const std::string& child_token);
 
+// Called in the parent process for each child process that is launched.
+// |process_error_callback| is called if the system becomes aware of some
+// internal error related to this process, e.g., if the system is notified of a
+// bad message from this process via the |MojoNotifyBadMessage()| API.
+MOJO_SYSTEM_IMPL_EXPORT void ChildProcessLaunched(
+    base::ProcessHandle child_process,
+    ScopedPlatformHandle server_pipe,
+    const std::string& child_token,
+    const ProcessErrorCallback& error_callback);
+
 // Called in the parent process when a child process fails to launch.
 // Exactly one of ChildProcessLaunched() or ChildProcessLaunchFailed() must be
 // called per child process launch attempt.