Clean up public interface of AttachmentBrokerUnprivileged.

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/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ skipping 79 matching lines @@
 
   // These two methods should only be called by the broker process.
   //
   // 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.
   virtual void RegisterCommunicationChannel(Endpoint* endpoint);
   virtual void DeregisterCommunicationChannel(Endpoint* endpoint);
 
+  // In each unprivileged process, exactly one channel should be used to
+  // communicate brokerable attachments with the broker process.
+  virtual void DesignateBrokerCommunicationChannel(Endpoint* endpoint);
+
+  // Whether the process's broker is privileged.

[Tom Sepez, 2016/02/09 00:26:19]

nit: True iff the process's broker is privileged.
(Just to be clear on the interpretation of the return value).

[erikchen, 2016/02/09 02:38:51]

Done.

+  virtual bool IsPrivilegedBroker();

[Tom Sepez, 2016/02/09 00:26:19]

Nit: maybe HasPrivilegedBroker(), because this process doesn't have an IS_A
relationship with broker classes.

[erikchen, 2016/02/09 02:38:51]

My initial comment was inaccurate in its use of the word "process's broker".
This is a IS_A relationship, since this is an instance method on
AttachmentBroker.

+
  protected:
   using AttachmentVector = std::vector<scoped_refptr<BrokerableAttachment>>;
 
   // Adds |attachment| to |attachments_|, and notifies the observers.
   void HandleReceivedAttachment(
       const scoped_refptr<BrokerableAttachment>& attachment);
 
   // Informs the observers that a new BrokerableAttachment has been received.
   void NotifyObservers(const BrokerableAttachment::AttachmentId& id);
 
@@ skipping 39 matching lines @@
 
   // The AttachmentBroker can be accessed from any thread, so modifications to
   // internal state must be guarded by a lock.
   base::Lock lock_;
   DISALLOW_COPY_AND_ASSIGN(AttachmentBroker);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_ATTACHMENT_BROKER_H_