Rename InvalidationVersionTracker to InvalidationStateTracker in preparation

sync/notifier/invalidation_state_tracker.h

Index: sync/notifier/invalidation_state_tracker.h
===================================================================
--- sync/notifier/invalidation_state_tracker.h	(revision 137282)
+++ sync/notifier/invalidation_state_tracker.h	(working copy)
@@ -5,8 +5,8 @@
 // An InvalidationVersionTracker is an interface that handles getting
 // and setting (persisting) max invalidation versions.
 
-#ifndef SYNC_NOTIFIER_INVALIDATION_VERSION_TRACKER_H_
-#define SYNC_NOTIFIER_INVALIDATION_VERSION_TRACKER_H_
+#ifndef SYNC_NOTIFIER_INVALIDATION_STATE_TRACKER_H_
+#define SYNC_NOTIFIER_INVALIDATION_STATE_TRACKER_H_
 
 #include <map>
 
@@ -17,9 +17,9 @@
 
 typedef std::map<syncable::ModelType, int64> InvalidationVersionMap;
 
-class InvalidationVersionTracker {
+class InvalidationStateTracker {
  public:
-  InvalidationVersionTracker() {}
+  InvalidationStateTracker() {}
 
   virtual InvalidationVersionMap GetAllMaxVersions() const = 0;
 
@@ -29,10 +29,9 @@
                              int64 max_version) = 0;
 
  protected:
-  virtual ~InvalidationVersionTracker() {}
+  virtual ~InvalidationStateTracker() {}
 };
 
 }  // namespace sync_notifier
 
-#endif  // SYNC_NOTIFIER_INVALIDATION_VERSION_TRACKER_H_
-
+#endif  // SYNC_NOTIFIER_INVALIDATION_STATE_TRACKER_H_