Reworks Channel pausing behavior

ipc/ipc_channel.h

 // Copyright (c) 2012 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_IPC_CHANNEL_H_
 #define IPC_IPC_CHANNEL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 204 matching lines @@
   // Connect the pipe.  On the server side, this will initiate
   // waiting for connections.  On the client, it attempts to
   // connect to a pre-existing pipe.  Note, calling Connect()
   // will not block the calling thread and may complete
   // asynchronously.
   //
   // The subclass implementation must call WillConnect() at the beginning of its
   // implementation.
   virtual bool Connect() WARN_UNUSED_RESULT = 0;
 
-  // Similar to (and exclusive to) Connect() above, but blocks outgoing messages
-  // until a future call to Unpause().
-  //
-  // Not all implementations support ConnectPaused(). Note that this interface
-  // exists only to facilitate weird behavior where some Channel consumers want
-  // to force some early messages to be transmitted before ones which were sent
-  // earlier. This allows that to be done without the consumer implementing
-  // their own message queueing support which may be incompatible with the
-  // Channel's internal queueing behavior.
-  virtual bool ConnectPaused() WARN_UNUSED_RESULT;
+  // Pause the channel. Subsequent sends will be queued internally until
+  // Unpause() is called and the channel is flushed either by Unpause() or a
+  // subsequent call to Flush().
+  virtual void Pause();
 
-  // Unpause the pipe. This allows subsequent Send() calls to transmit messages
-  // immediately, without queueing. If |flush| is true, any messages queued
-  // while paused will be flushed immediately upon unpausing. Otherwise you must
-  // call Flush() explicitly.
+  // Unpause the channel. This allows subsequent Send() calls to transmit
+  // messages immediately, without queueing. If |flush| is true, any messages
+  // queued while paused will be flushed immediately upon unpausing. Otherwise
+  // you must call Flush() explicitly.
   //
   // Not all implementations support Unpause(). See ConnectPaused() above for
   // details.
   virtual void Unpause(bool flush);
 
   // Manually flush the pipe. This is only useful exactly once, and only after
   // a call to Unpause(false), in order to explicitly flush out any
   // messages which were queued prior to unpausing.
   //
   // Not all implementations support Flush(). See ConnectPaused() above for
@@ skipping 118 matching lines @@
 
 #if defined(OS_POSIX)
 // SocketPair() creates a pair of socket FDs suitable for using with
 // IPC::Channel.
 IPC_EXPORT bool SocketPair(int* fd1, int* fd2);
 #endif
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_H_