Mojo C++ Bindings: Allow callbacks to own their InterfacePtr

mojo/public/cpp/bindings/lib/interface_endpoint_client.cc

 // Copyright 2015 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.
 
 #include "mojo/public/cpp/bindings/interface_endpoint_client.h"
 
 #include <stdint.h>
 
 #include <utility>
 
@@ skipping 262 matching lines @@
   return filters_.Accept(message);
 }
 
 void InterfaceEndpointClient::NotifyError() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (encountered_error_)
     return;
   encountered_error_ = true;
 
-  // The callbacks may hold on to resources. There is no need to keep them any
-  // longer.
-  async_responders_.clear();
+  // Response callbacks may hold on to resource, and there's no need to keep
+  // them alive any longer. Note that it's allowed that a pending response
+  // callback may own this endpoint, so we simply move the responders onto the
+  // stack here and let them be destroyed when the stack unwinds.
+  AsyncResponderMap responders = std::move(async_responders_);
 
   control_message_proxy_.OnConnectionError();
 
   if (!error_handler_.is_null()) {
     error_handler_.Run();
   } else if (!error_with_reason_handler_.is_null()) {
     // Make a copy on the stack. If we directly pass a reference to a member of
     // |control_message_handler_|, that reference will be invalidated as soon as
     // the user destroys the interface endpoint.
     std::string description = control_message_handler_.disconnect_description();
@@ skipping 51 matching lines @@
   observing_message_loop_destruction_ = false;
   base::MessageLoop::current()->RemoveDestructionObserver(this);
 }
 
 void InterfaceEndpointClient::WillDestroyCurrentMessageLoop() {
   StopObservingIfNecessary();
   NotifyError();
 }
 
 }  // namespace mojo