Reland of [VSync Queue] Plug touch ack to gesture events and flush vsync queue if necessary

content/browser/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/features.gni")
 import("//build/config/ui.gni")
 import("//gpu/vulkan/features.gni")
 import("//media/media_options.gni")
 import("//ppapi/features/features.gni")
 import("//printing/features/features.gni")
@@ skipping 2018 matching lines @@
     ]
   } else {  # Not aura.
     sources -= [
       "renderer_host/input/synthetic_gesture_target_aura.cc",
       "renderer_host/input/synthetic_gesture_target_aura.h",
       "renderer_host/input/touch_selection_controller_client_aura.cc",
       "renderer_host/input/touch_selection_controller_client_aura.h",
       "renderer_host/native_web_keyboard_event_aura.cc",
       "renderer_host/render_widget_host_view_aura.cc",
       "renderer_host/render_widget_host_view_aura.h",
-      "renderer_host/ui_events_helper.cc",
-      "renderer_host/ui_events_helper.h",
       "web_contents/aura/gesture_nav_simple.cc",
       "web_contents/aura/gesture_nav_simple.h",
       "web_contents/aura/overscroll_navigation_overlay.cc",
       "web_contents/aura/overscroll_navigation_overlay.h",
       "web_contents/aura/overscroll_window_animation.cc",
       "web_contents/aura/overscroll_window_animation.h",
       "web_contents/aura/overscroll_window_delegate.cc",
       "web_contents/aura/overscroll_window_delegate.h",
       "web_contents/aura/shadow_layer_delegate.cc",
       "web_contents/aura/shadow_layer_delegate.h",
@@ skipping 99 matching lines @@
   if (!is_component_build) {
     public_deps = [
       ":browser",
     ]
   } else {
     public_deps = [
       "//third_party/leveldatabase",
     ]
   }
 }