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

mojo/public/cpp/bindings/associated_interface_request.h

 // 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.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_REQUEST_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_REQUEST_H_
 
+#include <string>
 #include <utility>
 
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "mojo/public/cpp/bindings/interface_endpoint_client.h"
+#include "mojo/public/cpp/bindings/lib/control_message_proxy.h"
+#include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"
 
 namespace mojo {
 
 // AssociatedInterfaceRequest represents an associated interface request. It is
 // similar to InterfaceRequest except that it doesn't own a message pipe handle.
 template <typename Interface>
 class AssociatedInterfaceRequest {
  public:
   // Constructs an empty AssociatedInterfaceRequest, representing that the
@@ skipping 36 matching lines @@
 
   bool Equals(const AssociatedInterfaceRequest& 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;
+
+    if (!handle_.is_local()) {
+      // This handle is supposed to be sent to the other end of the message
+      // pipe and used there.
+      NOTREACHED();
+      handle_.reset();
+      return;
+    }
+
+    InterfaceEndpointClient client(std::move(handle_), nullptr,
+                                   base::MakeUnique<PassThroughFilter>(), false,
+                                   base::ThreadTaskRunnerHandle::Get(), 0u);
+    Message message =
+        internal::ControlMessageProxy::ConstructDisconnectReasonMessage(
+            custom_reason, description);
+    bool result = client.Accept(&message);
+    DCHECK(result);
+  }
+
  private:
   ScopedInterfaceEndpointHandle handle_;
 
   DISALLOW_COPY_AND_ASSIGN(AssociatedInterfaceRequest);
 };
 
 // Makes an AssociatedInterfaceRequest bound to the specified associated
 // endpoint.
 template <typename Interface>
 AssociatedInterfaceRequest<Interface> MakeAssociatedRequest(
     ScopedInterfaceEndpointHandle handle) {
   AssociatedInterfaceRequest<Interface> request;
   request.Bind(std::move(handle));
   return request;
 }
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_REQUEST_H_