Increase maximum file descriptors per IPC message on POSIX from 5 to 7

ipc/file_descriptor_set_posix.cc

 // Copyright (c) 2011 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/file_descriptor_set_posix.h"
 
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
@@ skipping 19 matching lines @@
   // kernel resources.
   for (unsigned i = consumed_descriptor_highwater_;
        i < descriptors_.size(); ++i) {
     if (descriptors_[i].auto_close)
       if (HANDLE_EINTR(close(descriptors_[i].fd)) < 0)
         PLOG(ERROR) << "close";
   }
 }
 
 bool FileDescriptorSet::Add(int fd) {
-  if (descriptors_.size() == kMaxDescriptorsPerMessage)
+  if (descriptors_.size() == kMaxDescriptorsPerMessage) {
+    DLOG(WARNING) << "Cannot add file descriptor. FileDescriptorSet full.";
     return false;
+  }
 
   struct base::FileDescriptor sd;
   sd.fd = fd;
   sd.auto_close = false;
   descriptors_.push_back(sd);
   return true;
 }
 
 bool FileDescriptorSet::AddAndAutoClose(int fd) {
-  if (descriptors_.size() == kMaxDescriptorsPerMessage)
+  if (descriptors_.size() == kMaxDescriptorsPerMessage) {
+    DLOG(WARNING) << "Cannot add file descriptor. FileDescriptorSet full.";
     return false;
+  }
 
   struct base::FileDescriptor sd;
   sd.fd = fd;
   sd.auto_close = true;
   descriptors_.push_back(sd);
   DCHECK(descriptors_.size() <= kMaxDescriptorsPerMessage);
   return true;
 }
 
 int FileDescriptorSet::GetDescriptorAt(unsigned index) const {
@@ skipping 65 matching lines @@
   DCHECK_EQ(consumed_descriptor_highwater_, 0u);
 
   descriptors_.reserve(count);
   for (unsigned i = 0; i < count; ++i) {
     struct base::FileDescriptor sd;
     sd.fd = buffer[i];
     sd.auto_close = true;
     descriptors_.push_back(sd);
   }
 }