cc/viz: Add some more flow trace-events.

Add some more flow trace-events for the various stages during a frame.
For example:
 . [client] Reception of BeginFrame (ReceiveBeginFrame).
 . [client] Generation of RenderPass, DrawQuad etc (GenerateRenderPass).
 . [client] Generation of CompositorFrame (GenerateCompositorFrame).
 . [client] Submission of CompositorFrame (SubmitCompositorFrame).
 . [server] Aggregation of surfaces from various clients in the
            DisplayCompositor (SurfaceAggregation).

An example screenshot: https://imgur.com/a/ZJGfq2J

BUG=855328

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Iccb7b61d485b20256cc8f35a5a4efef4c8ed63ea
Reviewed-on: https://chromium-review.googlesource.com/1116345Reviewed-by: Fady Samuel <fsamuel@chromium.org>
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570859}

cc/mojo_embedder/async_layer_tree_frame_sink.cc

@@ -120,6 +120,11 @@ void AsyncLayerTreeFrameSink::SubmitCompositorFrame(
   DCHECK(frame.metadata.begin_frame_ack.has_damage);
   DCHECK_LE(viz::BeginFrameArgs::kStartingFrameNumber,
             frame.metadata.begin_frame_ack.sequence_number);
+  TRACE_EVENT_WITH_FLOW1(
+      "viz,benchmark", "Graphics.Pipeline",
+      TRACE_ID_GLOBAL(frame.metadata.begin_frame_ack.trace_id),
+      TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT, "step",
+      "SubmitCompositorFrame");
 
   if (!enable_surface_synchronization_) {
     local_surface_id_ =
@@ -194,9 +199,18 @@ void AsyncLayerTreeFrameSink::DidPresentCompositorFrame(
 
 void AsyncLayerTreeFrameSink::OnBeginFrame(const viz::BeginFrameArgs& args) {
   if (!needs_begin_frames_) {
+    TRACE_EVENT_WITH_FLOW1("viz,benchmark", "Graphics.Pipeline",
+                           TRACE_ID_GLOBAL(args.trace_id),
+                           TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT,
+                           "step", "ReceiveBeginFrameDiscard");
     // We had a race with SetNeedsBeginFrame(false) and still need to let the
     // sink know that we didn't use this BeginFrame.
     DidNotProduceFrame(viz::BeginFrameAck(args, false));
+  } else {
+    TRACE_EVENT_WITH_FLOW1("viz,benchmark", "Graphics.Pipeline",
+                           TRACE_ID_GLOBAL(args.trace_id),
+                           TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT,
+                           "step", "ReceiveBeginFrame");
   }
   if (begin_frame_source_)
     begin_frame_source_->OnBeginFrame(args);

cc/trees/layer_tree_host_impl.cc

@@ -1277,6 +1277,10 @@ void LayerTreeHostImpl::InvalidateLayerTreeFrameSink(bool needs_redraw) {
 DrawResult LayerTreeHostImpl::PrepareToDraw(FrameData* frame) {
   TRACE_EVENT1("cc", "LayerTreeHostImpl::PrepareToDraw", "SourceFrameNumber",
                active_tree_->source_frame_number());
+  TRACE_EVENT_WITH_FLOW1("viz,benchmark", "Graphics.Pipeline",
+                         TRACE_ID_GLOBAL(CurrentBeginFrameArgs().trace_id),
+                         TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT,
+                         "step", "GenerateRenderPass");
   if (input_handler_client_)
     input_handler_client_->ReconcileElasticOverscrollAndRootScroll();
 
@@ -2013,9 +2017,6 @@ RenderFrameMetadata LayerTreeHostImpl::MakeRenderFrameMetadata(
 bool LayerTreeHostImpl::DrawLayers(FrameData* frame) {
   DCHECK(CanDraw());
   DCHECK_EQ(frame->has_no_damage, frame->render_passes.empty());
-
-  TRACE_EVENT0("cc,benchmark", "LayerTreeHostImpl::DrawLayers");
-
   ResetRequiresHighResToDraw();
   skipped_frame_tracker_.DidProduceFrame();
 
@@ -2027,6 +2028,36 @@ bool LayerTreeHostImpl::DrawLayers(FrameData* frame) {
     return false;
   }
 
+  auto compositor_frame = GenerateCompositorFrame(frame);
+  layer_tree_frame_sink_->SubmitCompositorFrame(std::move(compositor_frame));
+
+  // Clears the list of swap promises after calling DidSwap on each of them to
+  // signal that the swap is over.
+  active_tree()->ClearSwapPromises();
+
+  // The next frame should start by assuming nothing has changed, and changes
+  // are noted as they occur.
+  // TODO(boliu): If we did a temporary software renderer frame, propogate the
+  // damage forward to the next frame.
+  for (size_t i = 0; i < frame->render_surface_list->size(); i++) {
+    auto* surface = (*frame->render_surface_list)[i];
+    surface->damage_tracker()->DidDrawDamagedArea();
+  }
+  active_tree_->ResetAllChangeTracking();
+
+  active_tree_->set_has_ever_been_drawn(true);
+  devtools_instrumentation::DidDrawFrame(id_);
+  benchmark_instrumentation::IssueImplThreadRenderingStatsEvent(
+      rendering_stats_instrumentation_->TakeImplThreadRenderingStats());
+  return true;
+}
+
+viz::CompositorFrame LayerTreeHostImpl::GenerateCompositorFrame(
+    FrameData* frame) {
+  TRACE_EVENT_WITH_FLOW1("viz,benchmark", "Graphics.Pipeline",
+                         TRACE_ID_GLOBAL(CurrentBeginFrameArgs().trace_id),
+                         TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT,
+                         "step", "GenerateCompositorFrame");
   base::TimeTicks frame_time = CurrentBeginFrameArgs().frame_time;
   fps_counter_->SaveTimeStamp(frame_time,
                               !layer_tree_frame_sink_->context_provider());
@@ -2152,27 +2183,7 @@ bool LayerTreeHostImpl::DrawLayers(FrameData* frame) {
         total_quad_count);
   }
 
-  layer_tree_frame_sink_->SubmitCompositorFrame(std::move(compositor_frame));
-
-  // Clears the list of swap promises after calling DidSwap on each of them to
-  // signal that the swap is over.
-  active_tree()->ClearSwapPromises();
-
-  // The next frame should start by assuming nothing has changed, and changes
-  // are noted as they occur.
-  // TODO(boliu): If we did a temporary software renderer frame, propogate the
-  // damage forward to the next frame.
-  for (size_t i = 0; i < frame->render_surface_list->size(); i++) {
-    auto* surface = (*frame->render_surface_list)[i];
-    surface->damage_tracker()->DidDrawDamagedArea();
-  }
-  active_tree_->ResetAllChangeTracking();
-
-  active_tree_->set_has_ever_been_drawn(true);
-  devtools_instrumentation::DidDrawFrame(id_);
-  benchmark_instrumentation::IssueImplThreadRenderingStatsEvent(
-      rendering_stats_instrumentation_->TakeImplThreadRenderingStats());
-  return true;
+  return compositor_frame;
 }
 
 void LayerTreeHostImpl::DidDrawAllLayers(const FrameData& frame) {

cc/trees/layer_tree_host_impl.h

@@ -60,6 +60,7 @@ class ScrollOffset;
 }
 
 namespace viz {
+class CompositorFrame;
 class CompositorFrameMetadata;
 }
 
@@ -365,6 +366,7 @@ class CC_EXPORT LayerTreeHostImpl
   // called between the two.
   virtual DrawResult PrepareToDraw(FrameData* frame);
   virtual bool DrawLayers(FrameData* frame);
+  viz::CompositorFrame GenerateCompositorFrame(FrameData* frame);
   // Must be called if and only if PrepareToDraw was called.
   void DidDrawAllLayers(const FrameData& frame);
 

components/viz/service/display/surface_aggregator.cc

@@ -301,6 +301,11 @@ void SurfaceAggregator::EmitSurfaceContent(
 
   ++uma_stats_.valid_surface;
   const CompositorFrame& frame = surface->GetActiveFrame();
+  TRACE_EVENT_WITH_FLOW1(
+      "viz,benchmark", "Graphics.Pipeline",
+      TRACE_ID_GLOBAL(frame.metadata.begin_frame_ack.trace_id),
+      TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT, "step",
+      "SurfaceAggregation");
 
   if (ignore_undamaged) {
     gfx::Transform quad_to_target_transform(
@@ -1160,7 +1165,11 @@ CompositorFrame SurfaceAggregator::Aggregate(
     return {};
 
   const CompositorFrame& root_surface_frame = surface->GetActiveFrame();
-  TRACE_EVENT0("viz", "SurfaceAggregator::Aggregate");
+  TRACE_EVENT_WITH_FLOW1(
+      "viz,benchmark", "Graphics.Pipeline",
+      TRACE_ID_GLOBAL(root_surface_frame.metadata.begin_frame_ack.trace_id),
+      TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT, "step",
+      "SurfaceAggregation");
 
   CompositorFrame frame;
 

tools/perf/metrics/timeline.py

@@ -42,7 +42,7 @@ ReportSilkDetails = ["renderer_main"]
 # could change. We should formalize these traces to keep this robust.
 OverheadTraceCategory = "trace_event_overhead"
 OverheadTraceName = "overhead"
-FrameTraceName = "LayerTreeHostImpl::DrawLayers"
+FrameTraceName = "GenerateCompositorFrame"
 FrameTraceThreadName = "renderer_compositor"
 
 IntervalNames = ["frame", "second"]