Remove use of std::function from Mojo internals

mojo/edk/system/ports/message_queue.cc

 // Copyright 2016 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 "mojo/edk/system/ports/message_queue.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "mojo/edk/system/ports/event.h"
+#include "mojo/edk/system/ports/message_filter.h"
 
 namespace mojo {
 namespace edk {
 namespace ports {
 
 inline uint64_t GetSequenceNum(const ScopedMessage& message) {
   return GetEventData<UserEventData>(*message)->sequence_num;
 }
 
 // Used by std::{push,pop}_heap functions
@@ skipping 16 matching lines @@
     num_leaked_ports += message->num_ports();
   DVLOG_IF(1, num_leaked_ports > 0)
       << "Leaking " << num_leaked_ports << " ports in unreceived messages";
 #endif
 }
 
 bool MessageQueue::HasNextMessage() const {
   return !heap_.empty() && GetSequenceNum(heap_[0]) == next_sequence_num_;
 }
 
-void MessageQueue::GetNextMessageIf(
-    std::function<bool(const Message&)> selector,
-    ScopedMessage* message) {
-  if (!HasNextMessage() || (selector && !selector(*heap_[0].get()))) {
+void MessageQueue::GetNextMessage(ScopedMessage* message,
+                                  MessageFilter* filter) {
+  if (!HasNextMessage() || (filter && !filter->Match(*heap_[0].get()))) {
     message->reset();
     return;
   }
 
   std::pop_heap(heap_.begin(), heap_.end());
   *message = std::move(heap_.back());
   heap_.pop_back();
 
   next_sequence_num_++;
 }
@@ skipping 17 matching lines @@
 void MessageQueue::GetReferencedPorts(std::deque<PortName>* port_names) {
   for (const auto& message : heap_) {
     for (size_t i = 0; i < message->num_ports(); ++i)
       port_names->push_back(message->ports()[i]);
   }
 }
 
 }  // namespace ports
 }  // namespace edk
 }  // namespace mojo