ipc: Move methods into AttachmentBroker interface.

ipc/attachment_broker_privileged.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_PRIVILEGED_H_
 #define IPC_ATTACHMENT_BROKER_PRIVILEGED_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 15 matching lines @@
   ~AttachmentBrokerPrivileged() override;
 
    // On platforms that support attachment brokering, returns a new instance of
    // a platform-specific attachment broker. Otherwise returns |nullptr|.
    // The caller takes ownership of the newly created instance, and is
    // responsible for ensuring that the attachment broker lives longer than
    // every IPC::Channel. The new instance automatically registers itself as the
    // global attachment broker.
   static scoped_ptr<AttachmentBrokerPrivileged> CreateBroker();
 
-  // Each unprivileged process should have one IPC channel on which it
-  // communicates attachment information with the broker process. In the broker
-  // process, these channels must be registered and deregistered with the
-  // Attachment Broker as they are created and destroyed.
-  void RegisterCommunicationChannel(Endpoint* endpoint);
-  void DeregisterCommunicationChannel(Endpoint* endpoint);
+  // AttachmentBroker overrides.
+  void RegisterCommunicationChannel(Endpoint* endpoint) override;
+  void DeregisterCommunicationChannel(Endpoint* endpoint) override;
 
  protected:
   // Returns the sender whose peer's process id is |id|.
   // Returns nullptr if no sender is found.
   Sender* GetSenderWithProcessId(base::ProcessId id);
 
   // Errors that can be reported by subclasses.
   // These match tools/metrics/histograms.xml.
   // This enum is append-only.
   enum UMAError {
@@ skipping 12 matching lines @@
   void LogError(UMAError error);
 
  private:
   std::vector<Endpoint*> endpoints_;
   DISALLOW_COPY_AND_ASSIGN(AttachmentBrokerPrivileged);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_ATTACHMENT_BROKER_PRIVILEGED_H_