Revert of Convert //net and //chromecast to std::unordered_*

net/base/priority_queue.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 NET_BASE_PRIORITY_QUEUE_H_
 #define NET_BASE_PRIORITY_QUEUE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <list>
 #include <vector>
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/threading/non_thread_safe.h"
 #include "net/base/net_export.h"
 
 #if !defined(NDEBUG)
-#include <unordered_set>
+#include "base/containers/hash_tables.h"
 #endif
 
 namespace net {
 
 // A simple priority queue. The order of values is by priority and then FIFO.
 // Unlike the std::priority_queue, this implementation allows erasing elements
 // from the queue, and all operations are O(p) time for p priority levels.
 // The queue is agnostic to priority ordering (whether 0 precedes 1).
 // If the highest priority is 0, FirstMin() returns the first in order.
 //
@@ skipping 262 matching lines @@
   size_t size() const {
     DCHECK(CalledOnValidThread());
     return size_;
   }
 
  private:
   typedef std::vector<List> ListVector;
 
 #if !defined(NDEBUG)
   unsigned next_id_;
-  std::unordered_set<unsigned> valid_ids_;
+  base::hash_set<unsigned> valid_ids_;
 #endif
 
   ListVector lists_;
   size_t size_;
 
   DISALLOW_COPY_AND_ASSIGN(PriorityQueue);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_PRIORITY_QUEUE_H_