Include offscreen layers in generated trace

Flag: EXEMPT bugfix
Bug: 359854186
Test: winscope
Change-Id: Ia8572b4df1ac2921af3c4c686fc75062e1544c8c
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 9be9fee..79f11fb 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -5977,9 +5977,16 @@
         }
     }
 
-    return LayerProtoFromSnapshotGenerator(mLayerSnapshotBuilder, mFrontEndDisplayInfos,
-                                           mLegacyLayers, traceFlags)
-            .generate(mLayerHierarchyBuilder.getHierarchy());
+    auto traceGenerator =
+            LayerProtoFromSnapshotGenerator(mLayerSnapshotBuilder, mFrontEndDisplayInfos,
+                                            mLegacyLayers, traceFlags)
+                    .with(mLayerHierarchyBuilder.getHierarchy());
+
+    if (traceFlags & LayerTracing::Flag::TRACE_EXTRA) {
+        traceGenerator.withOffscreenLayers(mLayerHierarchyBuilder.getOffscreenHierarchy());
+    }
+
+    return traceGenerator.generate();
 }
 
 google::protobuf::RepeatedPtrField<perfetto::protos::DisplayProto>
@@ -6013,36 +6020,6 @@
     getHwComposer().dump(result);
 }
 
-void SurfaceFlinger::dumpOffscreenLayersProto(perfetto::protos::LayersProto& layersProto,
-                                              uint32_t traceFlags) const {
-    // Add a fake invisible root layer to the proto output and parent all the offscreen layers to
-    // it.
-    perfetto::protos::LayerProto* rootProto = layersProto.add_layers();
-    const int32_t offscreenRootLayerId = INT32_MAX - 2;
-    rootProto->set_id(offscreenRootLayerId);
-    rootProto->set_name("Offscreen Root");
-    rootProto->set_parent(-1);
-
-    perfetto::protos::LayersProto offscreenLayers =
-            LayerProtoFromSnapshotGenerator(mLayerSnapshotBuilder, mFrontEndDisplayInfos,
-                                            mLegacyLayers, traceFlags)
-                    .generate(mLayerHierarchyBuilder.getOffscreenHierarchy());
-
-    for (int i = 0; i < offscreenLayers.layers_size(); i++) {
-        perfetto::protos::LayerProto* layerProto = offscreenLayers.mutable_layers()->Mutable(i);
-        if (layerProto->parent() == -1) {
-            layerProto->set_parent(offscreenRootLayerId);
-            // Add layer as child of the fake root
-            rootProto->add_children(layerProto->id());
-        }
-    }
-
-    layersProto.mutable_layers()->Reserve(layersProto.layers_size() +
-                                          offscreenLayers.layers_size());
-    std::copy(offscreenLayers.layers().begin(), offscreenLayers.layers().end(),
-              RepeatedFieldBackInserter(layersProto.mutable_layers()));
-}
-
 perfetto::protos::LayersProto SurfaceFlinger::dumpProtoFromMainThread(uint32_t traceFlags) {
     return mScheduler
             ->schedule([=, this]() FTL_FAKE_GUARD(kMainThreadContext) {
@@ -8582,9 +8559,6 @@
                                             0);
 
     auto layers = dumpDrawingStateProto(traceFlags);
-    if (traceFlags & LayerTracing::Flag::TRACE_EXTRA) {
-        dumpOffscreenLayersProto(layers);
-    }
     *snapshot.mutable_layers() = std::move(layers);
 
     if (traceFlags & LayerTracing::Flag::TRACE_HWC) {