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 9b0aa5f20c0e69ce61bbdac930282acb177f5f21..be26bf69ac7f701cbf6c232317eb76f2158ab887 100644
--- a/components/viz/service/BUILD.gn
+++ b/components/viz/service/BUILD.gn
@@ -34,6 +34,8 @@ 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",
   ]
 
@@ -58,6 +60,7 @@ component("service") {
     "//cc/surfaces",
     "//gpu/command_buffer/client:gles2_interface",
     "//gpu/ipc:command_buffer",
+    "//services/viz/public/interfaces",
   ]
 
   if (is_mac) {
@@ -99,6 +102,7 @@ source_set("unit_tests") {
   sources = [
     "display_compositor/buffer_queue_unittest.cc",
     "display_compositor/server_shared_bitmap_manager_unittest.cc",
+    "hit_test/hit_test_aggregator_unittest.cc",
   ]
 
   if (!use_aura && !is_mac) {
@@ -116,6 +120,7 @@ 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",