Mojo C++ bindings: support closing [Associated]InterfaceRequest with reason.

mojo/public/cpp/bindings/interface_request.h

 // Copyright 2014 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_INTERFACE_REQUEST_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_REQUEST_H_
 
+#include <string>
 #include <utility>
 
 #include "base/macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "mojo/public/cpp/bindings/interface_ptr.h"
+#include "mojo/public/cpp/bindings/lib/control_message_proxy.h"
+#include "mojo/public/cpp/system/message_pipe.h"
 
 namespace mojo {
 
 // Represents a request from a remote client for an implementation of Interface
 // over a specified message pipe. The implementor of the interface should
 // remove the message pipe by calling PassMessagePipe() and bind it to the
 // implementation. If this is not done, the InterfaceRequest will automatically
 // close the pipe on destruction. Can also represent the absence of a request
 // if the client did not provide a message pipe.
 template <typename Interface>
@@ skipping 33 matching lines @@
 
   bool Equals(const InterfaceRequest& other) const {
     if (this == &other)
       return true;
 
     // Now that the two refer to different objects, they are equivalent if
     // and only if they are both invalid.
     return !is_pending() && !other.is_pending();
   }
 
+  void ResetWithReason(uint32_t custom_reason, const std::string& description) {
+    if (!handle_.is_valid())
+      return;
+
+    Message message =
+        internal::ControlMessageProxy::ConstructDisconnectReasonMessage(
+            custom_reason, description);
+    MojoResult result = WriteMessageNew(
+        handle_.get(), message.TakeMojoMessage(), MOJO_WRITE_MESSAGE_FLAG_NONE);
+    DCHECK_EQ(MOJO_RESULT_OK, result);
+
+    handle_.reset();
+  }
+
  private:
   ScopedMessagePipeHandle handle_;
 
   DISALLOW_COPY_AND_ASSIGN(InterfaceRequest);
 };
 
 // Makes an InterfaceRequest bound to the specified message pipe. If |handle|
 // is empty or invalid, the resulting InterfaceRequest will represent the
 // absence of a request.
 template <typename Interface>
@@ skipping 63 matching lines @@
 bool FuseInterface(InterfaceRequest<Interface> request,
                    InterfacePtrInfo<Interface> proxy_info) {
   MojoResult result = FuseMessagePipes(request.PassMessagePipe(),
                                        proxy_info.PassHandle());
   return result == MOJO_RESULT_OK;
 }
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_REQUEST_H_