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

components/sync/engine_impl/cycle/sync_cycle.h

Index: components/sync/engine_impl/cycle/sync_cycle.h
diff --git a/components/sync/sessions_impl/sync_session.h b/components/sync/engine_impl/cycle/sync_cycle.h
similarity index 66%
rename from components/sync/sessions_impl/sync_session.h
rename to components/sync/engine_impl/cycle/sync_cycle.h
index 1d633347f300c86ed91ed03c775dbf3c3035292e..2e0860687aece9c3bb0234524902b6be9d1f829b 100644
--- a/components/sync/sessions_impl/sync_session.h
+++ b/components/sync/engine_impl/cycle/sync_cycle.h
@@ -3,12 +3,12 @@
 // found in the LICENSE file.
 
 // A class representing an attempt to synchronize the local syncable data
-// store with a sync server. A SyncSession instance is passed as a stateful
-// bundle throughout the sync cycle.  The SyncSession is not reused across
+// store with a sync server. A SyncCycle instance is passed as a stateful
+// bundle throughout the sync cycle.  The SyncCycle is not reused across
 // sync cycles; each cycle starts with a new one.
 
-#ifndef COMPONENTS_SYNC_SESSIONS_IMPL_SYNC_SESSION_H_
-#define COMPONENTS_SYNC_SESSIONS_IMPL_SYNC_SESSION_H_
+#ifndef COMPONENTS_SYNC_ENGINE_IMPL_CYCLE_SYNC_CYCLE_H_
+#define COMPONENTS_SYNC_ENGINE_IMPL_CYCLE_SYNC_CYCLE_H_
 
 #include <map>
 #include <memory>
@@ -20,26 +20,24 @@
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "components/sync/base/model_type.h"
+#include "components/sync/engine/cycle/sync_cycle_snapshot.h"
 #include "components/sync/engine/model_safe_worker.h"
+#include "components/sync/engine_impl/cycle/status_controller.h"
+#include "components/sync/engine_impl/cycle/sync_cycle_context.h"
 #include "components/sync/engine_impl/sync_cycle_event.h"
 #include "components/sync/protocol/sync_protocol_error.h"
-#include "components/sync/sessions/sync_session_snapshot.h"
-#include "components/sync/sessions_impl/status_controller.h"
-#include "components/sync/sessions_impl/sync_session_context.h"
 
 namespace syncer {
-class ModelSafeWorker;
-class ProtocolEvent;
-
-namespace sessions {
 
+class ModelSafeWorker;
 class NudgeTracker;
+class ProtocolEvent;
 
-class SyncSession {
+class SyncCycle {
  public:
-  // The Delegate services events that occur during the session requiring an
-  // explicit (and session-global) action, as opposed to events that are simply
-  // recorded in per-session state.
+  // The Delegate services events that occur during the cycle requiring an
+  // explicit (and cycle-global) action, as opposed to events that are simply
+  // recorded in per-cycle state.
   class Delegate {
    public:
     // The client was throttled and should cease-and-desist syncing activity
@@ -50,14 +48,14 @@ class SyncSession {
     virtual void OnTypesThrottled(ModelTypeSet types,
                                   const base::TimeDelta& throttle_duration) = 0;
 
-    // Silenced intervals can be out of phase with individual sessions, so the
+    // Silenced intervals can be out of phase with individual cycles, so the
     // delegate is the only thing that can give an authoritative answer for
     // "is syncing silenced right now". This shouldn't be necessary very often
-    // as the delegate ensures no session is started if syncing is silenced.
+    // as the delegate ensures no cycle is started if syncing is silenced.
     // ** Note **  This will return true if silencing commenced during this
-    // session and the interval has not yet elapsed, but the contract here is
+    // cycle and the interval has not yet elapsed, but the contract here is
     // solely based on absolute time values. So, this cannot be used to infer
-    // that any given session _instance_ is silenced.  An example of reasonable
+    // that any given cycle _instance_ is silenced.  An example of reasonable
     // use is for UI reporting.
     virtual bool IsCurrentlyThrottled() = 0;
 
@@ -91,18 +89,18 @@ class SyncSession {
     virtual ~Delegate() {}
   };
 
-  // Build a session without a nudge tracker.  Used for poll or configure type
+  // Build a cycle without a nudge tracker.  Used for poll or configure type
   // sync cycles.
-  static SyncSession* Build(SyncSessionContext* context, Delegate* delegate);
-  ~SyncSession();
+  static SyncCycle* Build(SyncCycleContext* context, Delegate* delegate);
+  ~SyncCycle();
 
-  // Builds a thread-safe and read-only copy of the current session state.
-  SyncSessionSnapshot TakeSnapshot() const;
-  SyncSessionSnapshot TakeSnapshotWithSource(
+  // Builds a thread-safe and read-only copy of the current cycle state.
+  SyncCycleSnapshot TakeSnapshot() const;
+  SyncCycleSnapshot TakeSnapshotWithSource(
       sync_pb::GetUpdatesCallerInfo::GetUpdatesSource legacy_updates_source)
       const;
 
-  // Builds and sends a snapshot to the session context's listeners.
+  // Builds and sends a snapshot to the cycle context's listeners.
   void SendSyncCycleEndEventNotification(
       sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
   void SendEventNotification(SyncCycleEvent::EventCause cause);
@@ -110,7 +108,7 @@ class SyncSession {
   void SendProtocolEvent(const ProtocolEvent& event);
 
   // TODO(akalin): Split this into context() and mutable_context().
-  SyncSessionContext* context() const { return context_; }
+  SyncCycleContext* context() const { return context_; }
   Delegate* delegate() const { return delegate_; }
   const StatusController& status_controller() const {
     return *status_controller_.get();
@@ -120,21 +118,20 @@ class SyncSession {
   }
 
  private:
-  SyncSession(SyncSessionContext* context, Delegate* delegate);
+  SyncCycle(SyncCycleContext* context, Delegate* delegate);
 
-  // The context for this session, guaranteed to outlive |this|.
-  SyncSessionContext* const context_;
+  // The context for this cycle, guaranteed to outlive |this|.
+  SyncCycleContext* const context_;
 
-  // The delegate for this session, must never be NULL.
+  // The delegate for this cycle, must never be NULL.
   Delegate* const delegate_;
 
   // Our controller for various status and error counters.
   std::unique_ptr<StatusController> status_controller_;
 
-  DISALLOW_COPY_AND_ASSIGN(SyncSession);
+  DISALLOW_COPY_AND_ASSIGN(SyncCycle);
 };
 
-}  // namespace sessions
 }  // namespace syncer
 
-#endif  // COMPONENTS_SYNC_SESSIONS_IMPL_SYNC_SESSION_H_
+#endif  // COMPONENTS_SYNC_ENGINE_IMPL_CYCLE_SYNC_CYCLE_H_