chrome: Cleanup class/struct forward declarations

chrome/browser/chromeos/policy/heartbeat_scheduler.h

 // Copyright (c) 2015 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 CHROME_BROWSER_CHROMEOS_POLICY_HEARTBEAT_SCHEDULER_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_HEARTBEAT_SCHEDULER_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 12 matching lines @@
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace gcm {
 class GCMDriver;
 }
 
 namespace policy {
 
-class InstallAttributes;
 class HeartbeatRegistrationHelper;
 
 // Class responsible for periodically sending heartbeats to the policy service
 // for monitoring device connectivity.
 class HeartbeatScheduler : public gcm::GCMAppHandler,
                            gcm::GCMConnectionObserver {
  public:
   // Default interval for how often we send up a heartbeat.
   static const int64_t kDefaultHeartbeatIntervalMs;
 
@@ skipping 111 matching lines @@
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate the weak pointers before any other members are destroyed.
   base::WeakPtrFactory<HeartbeatScheduler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HeartbeatScheduler);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_HEARTBEAT_SCHEDULER_H_