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diff --git a/gpu/command_buffer/common/id_allocator.h b/gpu/command_buffer/common/id_allocator.h
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+// Copyright (c) 2009 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.
+
+// This file contains the definition of the IdAllocator class.
+
+#ifndef GPU_COMMAND_BUFFER_CLIENT_ID_ALLOCATOR_H_
+#define GPU_COMMAND_BUFFER_CLIENT_ID_ALLOCATOR_H_
+
+#include <set>
+#include <utility>
+#include "../common/types.h"
+
+namespace gpu {
+
+// A resource ID, key to the resource maps.
+typedef uint32 ResourceId;
+// Invalid resource ID.
+static const ResourceId kInvalidResource = 0u;
+
+// A class to manage the allocation of resource IDs.
+class IdAllocator {
+ public:
+  IdAllocator();
+
+  // Allocates a new resource ID.
+  ResourceId AllocateID() {
+    ResourceId id = FindFirstFree();
+    MarkAsUsed(id);
+    return id;
+  }
+
+  // Allocates an Id starting at or above desired_id.
+  // Note: may wrap if it starts near limit.
+  ResourceId AllocateIDAtOrAbove(ResourceId desired_id);
+
+  // Marks an id as used. Returns false if id was already used.
+  bool MarkAsUsed(ResourceId id) {
+    std::pair<ResourceIdSet::iterator, bool> result = used_ids_.insert(id);
+    return result.second;
+  }
+
+  // Frees a resource ID.
+  void FreeID(ResourceId id) {
+    used_ids_.erase(id);
+  }
+
+  // Checks whether or not a resource ID is in use.
+  bool InUse(ResourceId id) const {
+    return id == kInvalidResource || used_ids_.find(id) != used_ids_.end();
+  }
+
+ private:
+  // TODO(gman): This would work much better with ranges or a hash table.
+  typedef std::set<ResourceId> ResourceIdSet;
+
+  ResourceId FindFirstFree() const;
+
+  ResourceIdSet used_ids_;
+
+  DISALLOW_COPY_AND_ASSIGN(IdAllocator);
+};
+
+}  // namespace gpu
+
+#endif  // GPU_COMMAND_BUFFER_CLIENT_ID_ALLOCATOR_H_