Implement HitTestAggregator

components/viz/service/BUILD.gn

Index: components/viz/service/BUILD.gn
diff --git a/components/viz/service/BUILD.gn b/components/viz/service/BUILD.gn
index b5f8307518437443e6f7f87950013ab98a66c41a..4179d3b8250597d9d86246877b83ece2009095d0 100644
--- a/components/viz/service/BUILD.gn
+++ b/components/viz/service/BUILD.gn
@@ -32,6 +32,8 @@ component("service") {
     "frame_sinks/gpu_compositor_frame_sink_delegate.h",
     "frame_sinks/gpu_root_compositor_frame_sink.cc",
     "frame_sinks/gpu_root_compositor_frame_sink.h",
+    "hit_test/hit_test_aggregator.cc",
+    "hit_test/hit_test_aggregator.h",
     "viz_service_export.h",
   ]
 
@@ -56,6 +58,7 @@ component("service") {
     "//cc/surfaces",
     "//gpu/command_buffer/client:gles2_interface",
     "//gpu/ipc:command_buffer",
+    "//services/viz/public/interfaces",
   ]
 
   if (is_mac) {
@@ -97,6 +100,7 @@ source_set("unit_tests") {
   sources = [
     "display_compositor/buffer_queue_unittest.cc",
     "display_compositor/host_shared_bitmap_manager_unittest.cc",
+    "hit_test/hit_test_aggregator_unittest.cc",
   ]
 
   if (!use_aura && !is_mac) {
@@ -114,6 +118,7 @@ source_set("unit_tests") {
     "//base/test:test_support",
     "//cc:test_support",
     "//components/viz/common",
+    "//services/viz/public/interfaces",
     "//testing/gmock",
     "//testing/gtest",
     "//ui/display/types",