[layer tracing] generate composition state for non-default displays

Fixes: 264688936
Test: load multi display trace on winscope
Change-Id: Id6c07af31a3d1175b91c943e9d744a62cb9fbba5
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index a271083..968115c 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -8903,6 +8903,15 @@
     static_cast<void>(mScheduler->scheduleDelayed([&]() { scheduleRepaint(); }, ms2ns(delayInMs)));
 }
 
+const DisplayDevice* SurfaceFlinger::getDisplayFromLayerStack(ui::LayerStack layerStack) {
+    for (const auto& [_, display] : mDisplays) {
+        if (display->getLayerStack() == layerStack) {
+            return display.get();
+        }
+    }
+    return nullptr;
+}
+
 } // namespace android
 
 #if defined(__gl_h_)