Revert "DispSync: Always resync after inactivity"

This reverts commit f34b9be610ce286af224364cb6e69ef6f7697ee9.
Bug: 28160740

Change-Id: I48a5bd66712651b42fdc0aaf1492899d7b032977
diff --git a/services/surfaceflinger/EventThread.h b/services/surfaceflinger/EventThread.h
index 34654fa..9ba179a 100644
--- a/services/surfaceflinger/EventThread.h
+++ b/services/surfaceflinger/EventThread.h
@@ -77,7 +77,7 @@
 
 public:
 
-    EventThread(const sp<VSyncSource>& src, SurfaceFlinger& flinger);
+    EventThread(const sp<VSyncSource>& src);
 
     sp<Connection> createEventConnection() const;
     status_t registerDisplayEventConnection(const sp<Connection>& connection);
@@ -116,7 +116,6 @@
     // constants
     sp<VSyncSource> mVSyncSource;
     PowerHAL mPowerHAL;
-    SurfaceFlinger& mFlinger;
 
     mutable Mutex mLock;
     mutable Condition mCondition;