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 ecb8291d9c668d27a0d4eae05784858f362ccd8a..480a038ed99432f238269efffa4452c24560415b 100644
--- a/components/viz/service/BUILD.gn
+++ b/components/viz/service/BUILD.gn
@@ -37,6 +37,11 @@ component("service") {
     "frame_sinks/gpu_root_compositor_frame_sink.h",
     "frame_sinks/mojo_frame_sink_manager.cc",
     "frame_sinks/mojo_frame_sink_manager.h",
+    "hit_test/display_hit_test_data_factory.h",
+    "hit_test/display_hit_test_data_factory_local.cc",
+    "hit_test/display_hit_test_data_factory_local.h",
+    "hit_test/hit_test_aggregator.cc",
+    "hit_test/hit_test_aggregator.h",
     "viz_service_export.h",
   ]
 
@@ -54,6 +59,7 @@ component("service") {
     "//gpu/command_buffer/common",
     "//gpu/ipc:command_buffer",
     "//gpu/ipc/common:surface_handle_type",
+    "//services/viz/hit_test/public/interfaces",
     "//skia",
     "//ui/display/types",
     "//ui/gfx",
@@ -92,12 +98,34 @@ component("service") {
   }
 }
 
+test("hit_test_unit_tests") {
+  testonly = true
+  sources = [
+    "hit_test/hit_test_aggregator_unittest.cc",
+  ]
+  deps = [
+    ":service",
+    "//base",
+    "//base/test:test_support",
+    "//cc:test_support",
+    "//media",
+    "//mojo/edk/test:run_all_unittests",
+    "//services/viz/hit_test/public/interfaces",
+    "//skia",
+    "//testing/gmock",
+    "//testing/gtest",
+    "//ui/display/types",
+    "//ui/gl:test_support",
+  ]
+}
+
 # These are part of the components_unittests build target.
 source_set("unit_tests") {
   testonly = true
   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) {