Add Mojo API for Blink hit testing

content/renderer/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chromecast_build.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//content/common/features.gni")
 import("//media/media_options.gni")
@@ skipping 158 matching lines @@
     "input/main_thread_event_queue_task.h",
     "input/main_thread_event_queue_task_list.cc",
     "input/main_thread_event_queue_task_list.h",
     "input/main_thread_input_event_filter.cc",
     "input/main_thread_input_event_filter.h",
     "input/render_widget_input_handler.cc",
     "input/render_widget_input_handler.h",
     "input/render_widget_input_handler_delegate.h",
     "input/scoped_web_input_event_with_latency_info.cc",
     "input/scoped_web_input_event_with_latency_info.h",
+    "input/target_frame_for_input_impl.cc",
+    "input/target_frame_for_input_impl.h",
     "input/widget_input_handler_impl.cc",
     "input/widget_input_handler_impl.h",
     "input/widget_input_handler_manager.cc",
     "input/widget_input_handler_manager.h",
     "installedapp/related_apps_fetcher.cc",
     "installedapp/related_apps_fetcher.h",
     "internal_document_state_data.cc",
     "internal_document_state_data.h",
     "java/gin_java_bridge_dispatcher.cc",
     "java/gin_java_bridge_dispatcher.h",
@@ skipping 806 matching lines @@
 # See comment at the top of //content/BUILD.gn for how this works.
 group("for_content_tests") {
   visibility = [ "//content/test/*" ]
 
   if (!is_component_build) {
     public_deps = [
       ":renderer",
     ]
   }
 }