Use HitTestAggregator in GpuRootCompositorFrameSink

components/viz/frame_sinks/gpu_root_compositor_frame_sink.cc

Index: components/viz/frame_sinks/gpu_root_compositor_frame_sink.cc
diff --git a/components/viz/frame_sinks/gpu_root_compositor_frame_sink.cc b/components/viz/frame_sinks/gpu_root_compositor_frame_sink.cc
index 2804a0f34af0167b191ffee05cba9380cea82b8f..80ad7e79862c3aea05368d55deb8cc196f2ab709 100644
--- a/components/viz/frame_sinks/gpu_root_compositor_frame_sink.cc
+++ b/components/viz/frame_sinks/gpu_root_compositor_frame_sink.cc
@@ -4,8 +4,11 @@
 
 #include "components/viz/frame_sinks/gpu_root_compositor_frame_sink.h"
 
+#include "base/command_line.h"
 #include "cc/surfaces/compositor_frame_sink_support.h"
 #include "cc/surfaces/display.h"
+#include "components/viz/base/switches.h"
+#include "components/viz/hit_test/display_hit_test_data_factory_local.h"
 
 namespace viz {
 
@@ -46,6 +49,14 @@ GpuRootCompositorFrameSink::GpuRootCompositorFrameSink(
   surface_manager->RegisterBeginFrameSource(display_begin_frame_source_.get(),
                                             frame_sink_id);
   display_->Initialize(this, surface_manager);
+
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(

[Fady Samuel, 2017/06/15 15:02:40]

We are about to  introduce a bunch of flags. I suggest we create a
FrameSinkManagerSettings object that is populated prior to creation.

[gklassen, 2017/06/15 19:40:17]

Ok.  Can you send me a pointer to a pattern to follow and I will happily set
this up. 

+          switches::kUseVizHitTest)) {
+    auto display_hit_test_data_factory =
+        base::MakeUnique<hit_test::DisplayHitTestDataFactoryLocal>();
+    hit_test_aggregator_ = base::MakeUnique<hit_test::HitTestAggregator>(
+        std::move(display_hit_test_data_factory));
+  }
 }
 
 GpuRootCompositorFrameSink::~GpuRootCompositorFrameSink() {
@@ -115,7 +126,10 @@ void GpuRootCompositorFrameSink::DisplayOutputSurfaceLost() {
 
 void GpuRootCompositorFrameSink::DisplayWillDrawAndSwap(
     bool will_draw_and_swap,
-    const cc::RenderPassList& render_pass) {}
+    const cc::RenderPassList& render_pass) {
+  if (hit_test_aggregator_)
+    hit_test_aggregator_->PostTaskAggregate(display_->CurrentSurfaceId());
+}
 
 void GpuRootCompositorFrameSink::DisplayDidDrawAndSwap() {}
 
@@ -126,6 +140,8 @@ void GpuRootCompositorFrameSink::DidReceiveCompositorFrameAck(
 }
 
 void GpuRootCompositorFrameSink::OnBeginFrame(const cc::BeginFrameArgs& args) {
+  if (hit_test_aggregator_)
+    hit_test_aggregator_->Swap();
   if (client_)
     client_->OnBeginFrame(args);
 }