Stub in more IPC attachment brokering functionality.

ipc/attachment_broker.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 IPC_ATTACHMENT_BROKER_H_
 #define IPC_ATTACHMENT_BROKER_H_
 
 #include "base/macros.h"
 #include "base/process/process_handle.h"
 #include "ipc/brokerable_attachment.h"
@@ skipping 16 matching lines @@
 // that support attachment brokering, every IPC channel should have a reference
 // to a AttachmentBroker.
 class IPC_EXPORT AttachmentBroker {
  public:
   AttachmentBroker() {}
   virtual ~AttachmentBroker() {}
 
   // Sends |attachment| to |destination_process|. The implementation uses an
   // IPC::Channel to communicate with the broker process. This may be the same
   // IPC::Channel that is requesting the brokering of an attachment.
-  virtual void SendAttachmentToProcess(BrokerableAttachment* attachment,
+  // Returns true on success and false otherwise.
+  virtual bool SendAttachmentToProcess(BrokerableAttachment* attachment,
                                        base::ProcessId destination_process) = 0;
 
   // Returns whether the attachment was available. If the attachment was
   // available, populates the output parameter |attachment|. The caller then
   // becomes the owner of |attachment|.
   virtual bool GetAttachmentWithId(BrokerableAttachment::AttachmentId id,
                                    BrokerableAttachment* attachment) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AttachmentBroker);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_ATTACHMENT_BROKER_H_