update_engine: Relocate data member declaration.

Per style, data members come after all method declarations.

BUG=None
TEST=None

Change-Id: Ica1d6a3c5e150d32d7386c124b8824a962295d63
Reviewed-on: https://chromium-review.googlesource.com/221199
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
Tested-by: Gilad Arnold <garnold@chromium.org>
diff --git a/payload_state.h b/payload_state.h
index 34f2e53..99e7d84 100644
--- a/payload_state.h
+++ b/payload_state.h
@@ -350,9 +350,6 @@
   // metric that is reported once the new update was applied.
   void ReportUpdatesAbandonedEventCountMetric();
 
-  // The global state of the system.
-  SystemState* system_state_;
-
   // Initializes |num_reboots_| from the persisted state.
   void LoadNumReboots();
 
@@ -389,6 +386,9 @@
   // Sets the |kPrefsP2PFirstAttemptTimestamp| state variable to |time|.
   void SetP2PFirstAttemptTimestamp(const base::Time& time);
 
+  // The global state of the system.
+  SystemState* system_state_;
+
   // Interface object with which we read/write persisted state. This must
   // be set by calling the Initialize method before calling any other method.
   PrefsInterface* prefs_;