C++ bindings: support using a callback as connection error handler.

mojo/public/cpp/bindings/lib/connector.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_CONNECTOR_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_CONNECTOR_H_
 
 #include "mojo/public/c/environment/async_waiter.h"
+#include "mojo/public/cpp/bindings/callback.h"
 #include "mojo/public/cpp/bindings/lib/message_queue.h"
 #include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/system/core.h"
 
 namespace mojo {
 class ErrorHandler;
 
 namespace internal {
 
@@ skipping 21 matching lines @@
 
   // Errors from incoming receivers will force the connector into an error
   // state, where no more messages will be processed. This method is used
   // during testing to prevent that from happening.
   void set_enforce_errors_from_incoming_receiver(bool enforce) {
     enforce_errors_from_incoming_receiver_ = enforce;
   }
 
   // Sets the error handler to receive notifications when an error is
   // encountered while reading from the pipe or waiting to read from the pipe.
-  void set_error_handler(ErrorHandler* error_handler) {
-    error_handler_ = error_handler;
+  void set_connection_error_handler(const Closure& error_handler) {
+    connection_error_handler_ = error_handler;
   }
 
   // Returns true if an error was encountered while reading from the pipe or
   // waiting to read from the pipe.
   bool encountered_error() const { return error_; }
 
   // Closes the pipe, triggering the error state. Connector is put into a
   // quiescent state.
   void CloseMessagePipe();
 
@@ skipping 24 matching lines @@
   MOJO_WARN_UNUSED_RESULT bool ReadSingleMessage(MojoResult* read_result);
 
   // |this| can be destroyed during message dispatch.
   void ReadAllAvailableMessages();
 
   void NotifyError();
 
   // Cancels any calls made to |waiter_|.
   void CancelWait();
 
-  ErrorHandler* error_handler_;
+  Closure connection_error_handler_;
   const MojoAsyncWaiter* waiter_;
 
   ScopedMessagePipeHandle message_pipe_;
   MessageReceiver* incoming_receiver_;
 
   MojoAsyncWaitID async_wait_id_;
   bool error_;
   bool drop_writes_;
   bool enforce_errors_from_incoming_receiver_;
 
   // If non-null, this will be set to true when the Connector is destroyed.  We
   // use this flag to allow for the Connector to be destroyed as a side-effect
   // of dispatching an incoming message.
   bool* destroyed_flag_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(Connector);
 };
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_CONNECTOR_H_