Remove the extension QuotaService::SustainedLimit and its last client, the

extensions/browser/quota_service.h

Index: extensions/browser/quota_service.h
diff --git a/extensions/browser/quota_service.h b/extensions/browser/quota_service.h
index 791b67fc10502b484b81d7e759ea99faa4ef8063..1dd55699e3eb7e0c427f5904df213674353391a0 100644
--- a/extensions/browser/quota_service.h
+++ b/extensions/browser/quota_service.h
@@ -45,7 +45,6 @@ class QuotaService : public base::NonThreadSafe {
   // Some concrete heuristics (declared below) that ExtensionFunctions can
   // use to help the service make decisions about quota violations.
   class TimedLimit;
-  class SustainedLimit;
 
   QuotaService();
   virtual ~QuotaService();
@@ -216,24 +215,6 @@ class QuotaService::TimedLimit : public QuotaLimitHeuristic {
   bool Apply(Bucket* bucket, const base::TimeTicks& event_time) override;
 };
 
-// A per-item heuristic to limit the number of events that can occur in a
-// period of time over a sustained longer interval. E.g "no more than two
-// events per minute, sustained over 10 minutes".
-class QuotaService::SustainedLimit : public QuotaLimitHeuristic {
- public:
-  SustainedLimit(const base::TimeDelta& sustain,
-                 const Config& config,
-                 BucketMapper* map,
-                 const std::string& name);
-  bool Apply(Bucket* bucket, const base::TimeTicks& event_time) override;
-
- private:
-  // Specifies how long exhaustion of buckets is allowed to continue before
-  // denying requests.
-  const int64 repeat_exhaustion_allowance_;
-  int64 num_available_repeat_exhaustions_;
-};
-
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_QUOTA_SERVICE_H_