WIP: Plumbing input event latency reporting through Mus GPU.

services/ui/surfaces/display_output_surface.cc

Index: services/ui/surfaces/display_output_surface.cc
diff --git a/services/ui/surfaces/display_output_surface.cc b/services/ui/surfaces/display_output_surface.cc
index 85ece68dd7dfaa9e5d9c8c295e188d26eab6ab94..44ba93cf1b8405eedb605cefeeee1bf246d5cd74 100644
--- a/services/ui/surfaces/display_output_surface.cc
+++ b/services/ui/surfaces/display_output_surface.cc
@@ -15,6 +15,7 @@
 #include "cc/scheduler/begin_frame_source.h"
 #include "gpu/command_buffer/client/context_support.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
+#include "ui/latency/latency_tracker.h"
 
 namespace ui {
 
@@ -23,6 +24,7 @@ DisplayOutputSurface::DisplayOutputSurface(
     cc::SyntheticBeginFrameSource* synthetic_begin_frame_source)
     : cc::OutputSurface(context_provider),
       synthetic_begin_frame_source_(synthetic_begin_frame_source),
+      latency_tracker_(new LatencyTracker),
       weak_ptr_factory_(this) {
   capabilities_.flipped_output_surface =
       context_provider->ContextCapabilities().flips_vertically;
@@ -79,12 +81,16 @@ void DisplayOutputSurface::Reshape(const gfx::Size& size,
 
 void DisplayOutputSurface::SwapBuffers(cc::OutputSurfaceFrame frame) {
   DCHECK(context_provider_);
+
+  if (frame.latency_info.size() > 0)
+    context_provider_->ContextSupport()->AddLatencyInfo(frame.latency_info);
+
   set_draw_rectangle_for_frame_ = false;
   if (frame.sub_buffer_rect) {
     context_provider_->ContextSupport()->PartialSwapBuffers(
         *frame.sub_buffer_rect);
   } else {
-    context_provider_->ContextSupport()->Swap();
+    context_provider_->ContextSupport()->Swap(/*frame.latency_info*/);
   }
 }
 
@@ -123,9 +129,13 @@ void DisplayOutputSurface::DidReceiveSwapBuffersAck(gfx::SwapResult result) {
 }
 
 void DisplayOutputSurface::OnGpuSwapBuffersCompleted(
-    const std::vector<ui::LatencyInfo>& latency_info,
+    const std::vector<LatencyInfo>& latency_info,
     gfx::SwapResult result,
     const gpu::GpuProcessHostedCALayerTreeParamsMac* params_mac) {
+  for (const auto& latency : latency_info) {
+    if (latency.latency_components().size() > 0)
+      latency_tracker_->OnGpuSwapBuffersCompleted(latency);
+  }
   DidReceiveSwapBuffersAck(result);
 }