Framework code for Attached Choreographer.

Allows a direct association of a Layer (via LayerHistory) to attached
choreographer.
The EventThread checks whether the vsync is in phase for a
choreographer.

Bug: 255838011
Test: atest AttachedChoreographerNativeTest
Change-Id: I9cb35bced5e6d4509609ad7698ab2902a31d5b98
diff --git a/services/surfaceflinger/Scheduler/LayerHistory.h b/services/surfaceflinger/Scheduler/LayerHistory.h
index 5022906..68e7030 100644
--- a/services/surfaceflinger/Scheduler/LayerHistory.h
+++ b/services/surfaceflinger/Scheduler/LayerHistory.h
@@ -27,6 +27,8 @@
 #include <utility>
 #include <vector>
 
+#include "EventThread.h"
+
 #include "RefreshRateSelector.h"
 
 namespace android {
@@ -80,6 +82,9 @@
     // return the frames per second of the layer with the given sequence id.
     float getLayerFramerate(nsecs_t now, int32_t id) const;
 
+    void attachChoreographer(int32_t layerId,
+                             const sp<EventThreadConnection>& choreographerConnection);
+
 private:
     friend class LayerHistoryTest;
     friend class TestableScheduler;
@@ -117,6 +122,10 @@
     LayerInfos mActiveLayerInfos GUARDED_BY(mLock);
     LayerInfos mInactiveLayerInfos GUARDED_BY(mLock);
 
+    // Map keyed by layer ID (sequence) to choreographer connections.
+    std::unordered_multimap<int32_t, wp<EventThreadConnection>> mAttachedChoreographers
+            GUARDED_BY(mLock);
+
     uint32_t mDisplayArea = 0;
 
     // Whether to emit systrace output and debug logs.