SF: Pass timestamps into layer tracing

This will allow us to recreate layer traces that
reflect the same timeline as the transaction
trace.

Test: presubmit
Bug: 200284593

Change-Id: I693c514ae56ed2137ad53b007a6722ba9396ecde
diff --git a/services/surfaceflinger/Tracing/LayerTracing.cpp b/services/surfaceflinger/Tracing/LayerTracing.cpp
index d136e0b..006efdf 100644
--- a/services/surfaceflinger/Tracing/LayerTracing.cpp
+++ b/services/surfaceflinger/Tracing/LayerTracing.cpp
@@ -98,16 +98,20 @@
     mBuffer->dump(result);
 }
 
-void LayerTracing::notify(const char* where) {
-    ATRACE_CALL();
+void LayerTracing::notify(bool visibleRegionDirty, int64_t time) {
     std::scoped_lock lock(mTraceLock);
     if (!mEnabled) {
         return;
     }
 
+    if (!visibleRegionDirty && !flagIsSet(LayerTracing::TRACE_BUFFERS)) {
+        return;
+    }
+
     ATRACE_CALL();
     LayersTraceProto entry;
-    entry.set_elapsed_realtime_nanos(elapsedRealtimeNano());
+    entry.set_elapsed_realtime_nanos(time);
+    const char* where = visibleRegionDirty ? "visibleRegionsDirty" : "bufferLatched";
     entry.set_where(where);
     LayersProto layers(mFlinger.dumpDrawingStateProto(mFlags));