[Sync] Move sessions/ to engine/cycle/ and rename things to match.

components/sync/engine_impl/backoff_delay_provider.h

 // Copyright 2012 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_SYNC_ENGINE_IMPL_BACKOFF_DELAY_PROVIDER_H_
 #define COMPONENTS_SYNC_ENGINE_IMPL_BACKOFF_DELAY_PROVIDER_H_
 
 #include "base/macros.h"
 #include "base/time/time.h"
 
 namespace syncer {
 
-namespace sessions {
 struct ModelNeutralState;
-}
 
 // A component used to get time delays associated with exponential backoff.
 class BackoffDelayProvider {
  public:
   // Factory function to create a standard BackoffDelayProvider.
   static BackoffDelayProvider* FromDefaults();
 
   // Similar to above, but causes sync to retry very quickly (see
   // polling_constants.h) when it encounters an error before exponential
   // backoff.
   //
   // *** NOTE *** This should only be used if kSyncShortInitialRetryOverride
   // was passed to command line.
   static BackoffDelayProvider* WithShortInitialRetryOverride();
 
   virtual ~BackoffDelayProvider();
 
   // DDOS avoidance function.  Calculates how long we should wait before trying
   // again after a failed sync attempt, where the last delay was |base_delay|.
   // TODO(tim): Look at URLRequestThrottlerEntryInterface.
   virtual base::TimeDelta GetDelay(const base::TimeDelta& last_delay);
 
   // Helper to calculate the initial value for exponential backoff.
   // See possible values and comments in polling_constants.h.
-  virtual base::TimeDelta GetInitialDelay(
-      const sessions::ModelNeutralState& state) const;
+  virtual base::TimeDelta GetInitialDelay(const ModelNeutralState& state) const;
 
  protected:
   BackoffDelayProvider(const base::TimeDelta& default_initial_backoff,
                        const base::TimeDelta& short_initial_backoff);
 
  private:
   const base::TimeDelta default_initial_backoff_;
   const base::TimeDelta short_initial_backoff_;
 
   DISALLOW_COPY_AND_ASSIGN(BackoffDelayProvider);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_IMPL_BACKOFF_DELAY_PROVIDER_H_