Add paranoid logging to ChannelImpl::ProcessOutgoingMessages() to help track down bug.

ipc/ipc_channel_posix.cc

 // Copyright (c) 2008 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.
 
 #include "ipc/ipc_channel_posix.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stddef.h>
 #include <sys/types.h>
@@ skipping 807 matching lines @@
       // On OSX writing to a pipe with no listener returns EPERM.
       if (errno == EPERM) {
         Close();
         return false;
       }
 #endif  // OS_MACOSX
       if (errno == EPIPE) {
         Close();
         return false;
       }
-      PLOG(ERROR) << "pipe error on " << fd_written;
+      PLOG(ERROR) << "pipe error on "
+                  << fd_written
+                  << " Currently writing message of size:"
+                  << msg->size()
+                  << " msgh.msg_iovlen:"
+                  << msgh.msg_iovlen
+                  << " amt_to_write: "
+                  << amt_to_write
+                  << " num FDs to send:"
+                  << msg->file_descriptor_set()->size();
       return false;
     }
 
     if (static_cast<size_t>(bytes_written) != amt_to_write) {
       if (bytes_written > 0) {
         // If write() fails with EAGAIN then bytes_written will be -1.
         message_send_bytes_written_ += bytes_written;
       }
 
       // Tell libevent to call us back once things are unblocked.
@@ skipping 180 matching lines @@
 
 bool Channel::Send(Message* message) {
   return channel_impl_->Send(message);
 }
 
 int Channel::GetClientFileDescriptor() const {
   return channel_impl_->GetClientFileDescriptor();
 }
 
 }  // namespace IPC