Allow std::unordered_*.

cc/quads/render_pass_id.h

 // Copyright 2014 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 CC_QUADS_RENDER_PASS_ID_H_
 #define CC_QUADS_RENDER_PASS_ID_H_
 
 #include <stddef.h>
 
 #include <tuple>
 
-#include "base/containers/hash_tables.h"
 #include "cc/base/cc_export.h"
 
 namespace cc {
 
 class CC_EXPORT RenderPassId {
  public:
   int layer_id;
   size_t index;
 
   RenderPassId() : layer_id(-1), index(0) {}
   RenderPassId(int layer_id, size_t index) : layer_id(layer_id), index(index) {}
   void* AsTracingId() const;
 
   bool IsValid() const { return layer_id >= 0; }
 
   bool operator==(const RenderPassId& other) const {
     return layer_id == other.layer_id && index == other.index;
   }
   bool operator!=(const RenderPassId& other) const { return !(*this == other); }
   bool operator<(const RenderPassId& other) const {
     return std::tie(layer_id, index) < std::tie(other.layer_id, other.index);
   }
 };
 
 }  // namespace cc
 
 #endif  // CC_QUADS_RENDER_PASS_ID_H_