[GRC] Process Coordination Unit support for Global Resource Controller

services/resource_coordinator/public/cpp/coordination_unit_id.h

 // Copyright 2017 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 SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_ID_H_
 #define SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_ID_H_
 
 #include <string>
 
 #include "services/resource_coordinator/public/cpp/coordination_unit_types.h"
 #include "services/resource_coordinator/public/cpp/resource_coordinator_export.h"
 
 namespace resource_coordinator {
 
 // This is a native struct rather than a mojom struct as we eventually want
 // to annotate base::TaskRunner with CUs for cost attribution purses and
 // would like to move it to base/ as easily as possible at that point.
+// TODO(oysteine): Rename to CoordinationUnitGUID to better differentiate the
+// class from the internal id
 struct SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_EXPORT CoordinationUnitID {
+  typedef uint64_t CoordinationUnitTypeId;
+
   CoordinationUnitID();
   CoordinationUnitID(const CoordinationUnitType& type,
                      const std::string& new_id);
+  CoordinationUnitID(const CoordinationUnitType& type,
+                     CoordinationUnitTypeId new_id);
 
   bool operator==(const CoordinationUnitID& b) const {
     return id == b.id && type == b.type;
   }
 
-  int64_t id;
+  CoordinationUnitTypeId id;
   CoordinationUnitType type;
 };
 
 }  // resource_coordinator
 
 namespace std {
 
 template <>
 struct hash<resource_coordinator::CoordinationUnitID> {
   uint64_t operator()(
       const resource_coordinator::CoordinationUnitID& id) const {
-    return ((static_cast<uint64_t>(id.type)) << 32) | id.id;
+    return ((static_cast<uint64_t>(id.type)) << 32) |
+           static_cast<uint64_t>(id.id);
   }
 };
 
 }  // namespace std
 
 #endif  // SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_ID_H_