Support repurposing idle timer to work with kernel timer.

Idle timer would instead enable/disable hw vsyncs in accordance with
inactivity.

Bug: 130684082
Test: systrace
Change-Id: I289600fc41b7ded863c9486cf6c2ab6155b06550
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 34327b5..c8ff377 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -157,6 +157,7 @@
     void updateFpsBasedOnContent();
     // Callback that gets invoked when Scheduler wants to change the refresh rate.
     void setChangeRefreshRateCallback(const ChangeRefreshRateCallback& changeRefreshRateCallback);
+    void setGetVsyncPeriodCallback(const GetVsyncPeriod&& getVsyncPeriod);
 
     // Returns whether idle timer is enabled or not
     bool isIdleTimerEnabled() { return mSetIdleTimerMs > 0; }
@@ -191,6 +192,14 @@
     void resetTimerCallback();
     // Function that is called when the timer expires.
     void expiredTimerCallback();
+    // Function that is called when the timer resets when paired with a display
+    // driver timeout in the kernel. This enables hardware vsync when we move
+    // out from idle.
+    void resetKernelTimerCallback();
+    // Function that is called when the timer expires when paired with a display
+    // driver timeout in the kernel. This disables hardware vsync when we move
+    // into idle.
+    void expiredKernelTimerCallback();
     // Sets vsync period.
     void setVsyncPeriod(const nsecs_t period);
     // Idle timer feature's function to change the refresh rate.
@@ -242,9 +251,13 @@
     // interval, a callback is fired. Set this variable to >0 to use this feature.
     int64_t mSetIdleTimerMs = 0;
     std::unique_ptr<scheduler::IdleTimer> mIdleTimer;
+    // Enables whether to use idle timer callbacks that support the kernel
+    // timer.
+    bool mSupportKernelTimer;
 
     std::mutex mCallbackLock;
     ChangeRefreshRateCallback mChangeRefreshRateCallback GUARDED_BY(mCallbackLock);
+    GetVsyncPeriod mGetVsyncPeriod GUARDED_BY(mCallbackLock);
 
     // In order to make sure that the features don't override themselves, we need a state machine
     // to keep track which feature requested the config change.