[BackgroundSync Cleanup] Remove power observer

content/browser/background_sync/background_sync_registration_options.h

 // Copyright 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 CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_REGISTRATION_OPTIONS_H_
 #define CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_REGISTRATION_OPTIONS_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "content/browser/background_sync/background_sync.pb.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
 // The options passed to BackgroundSyncManager::Registration.
 struct CONTENT_EXPORT BackgroundSyncRegistrationOptions {
   bool Equals(const BackgroundSyncRegistrationOptions& other) const;
 
   std::string tag;
   int64_t min_period = 0;
   SyncNetworkState network_state = NETWORK_STATE_ONLINE;
-  SyncPowerState power_state = POWER_STATE_AVOID_DRAINING;
   SyncPeriodicity periodicity = SYNC_ONE_SHOT;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BACKGROUND_SYNC_BACKGROUND_SYNC_REGISTRATION_OPTIONS_H_