components: Cleanup class/struct fwd declarations

components/domain_reliability/dispatcher.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 COMPONENTS_DOMAIN_RELIABILITY_DISPATCHER_H_
 #define COMPONENTS_DOMAIN_RELIABILITY_DISPATCHER_H_
 
 #include <memory>
 #include <set>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "components/domain_reliability/domain_reliability_export.h"
 
-namespace tracked_objects {
-class Location;
-}  // namespace tracked_objects
-
 namespace domain_reliability {
 
 class MockableTime;
 
 // Runs tasks during a specified interval. Calling |RunEligibleTasks| gives any
 // task a chance to run early (if the minimum delay has already passed); tasks
 // that aren't run early will be run once their maximum delay has passed.
 //
 // (See scheduler.h for an explanation of how the intervals are chosen.)
 class DOMAIN_RELIABILITY_EXPORT DomainReliabilityDispatcher {
@@ skipping 28 matching lines @@
   MockableTime* time_;
   std::set<std::unique_ptr<Task>> tasks_;
   std::set<Task*> eligible_tasks_;
 
   DISALLOW_COPY_AND_ASSIGN(DomainReliabilityDispatcher);
 };
 
 }  // namespace domain_reliability
 
 #endif