Do not typedef ExtensionId/ID, since it's already available in extension_id.h

extensions/browser/quota_service.h

 // Copyright 2013 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.
 
 // The QuotaService uses heuristics to limit abusive requests
 // made by extensions.  In this model 'items' (e.g individual bookmarks) are
 // represented by a 'Bucket' that holds state for that item for one single
 // interval of time.  The interval of time is defined as 'how long we need to
 // watch an item (for a particular heuristic) before making a decision about
 // quota violations'.  A heuristic is two functions: one mapping input
@@ skipping 10 matching lines @@
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "base/values.h"
+#include "extensions/common/extension_id.h"
 
 class ExtensionFunction;
 
 namespace extensions {
 class QuotaLimitHeuristic;
 
 using QuotaLimitHeuristics = std::list<std::unique_ptr<QuotaLimitHeuristic>>;
 
 // The QuotaService takes care that calls to certain extension
 // functions do not exceed predefined quotas.
@@ skipping 25 matching lines @@
   class ScopedDisablePurgeForTesting {
    public:
     ScopedDisablePurgeForTesting();
     ~ScopedDisablePurgeForTesting();
 
    private:
     DISALLOW_COPY_AND_ASSIGN(ScopedDisablePurgeForTesting);
   };
 
  private:
-  using ExtensionId = std::string;
   using FunctionName = std::string;
   // All QuotaLimitHeuristic instances in this map are owned by us.
   using FunctionHeuristicsMap = std::map<FunctionName, QuotaLimitHeuristics>;
 
   // Purge resets all accumulated data as if the service was just created.
   // Called periodically so we don't consume an unbounded amount of memory
   // while tracking quota.
   void Purge();
   base::RepeatingTimer purge_timer_;
 
@@ skipping 128 matching lines @@
 class QuotaService::TimedLimit : public QuotaLimitHeuristic {
  public:
   TimedLimit(const Config& config, BucketMapper* map, const std::string& name)
       : QuotaLimitHeuristic(config, map, name) {}
   bool Apply(Bucket* bucket, const base::TimeTicks& event_time) override;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_QUOTA_SERVICE_H_