cast: Support for low-latency interactive mode

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("//content/browser/browser.gni")
 import("//media/media_options.gni")
 
 source_set("browser") {
@@ skipping 430 matching lines @@
       "web_contents/web_contents_view_mus.h",
     ]
     if (toolkit_views) {
       deps += [ "//ui/views/mus:for_component" ]
       defines += [ "MOJO_RUNNER_CLIENT" ]
     }
   } else {  # Not aura.
     sources -= [
       "media/capture/cursor_renderer_aura.cc",
       "media/capture/cursor_renderer_aura.h",
+      "media/capture/window_activity_tracker_aura.cc",
+      "media/capture/window_activity_tracker_aura.h",
       "renderer_host/compositor_resize_lock_aura.cc",
       "renderer_host/compositor_resize_lock_aura.h",
       "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",
@@ skipping 86 matching lines @@
 
   if (enable_webvr && is_android) {
     sources += [
       "vr/android/cardboard/cardboard_vr_device.cc",
       "vr/android/cardboard/cardboard_vr_device.h",
       "vr/android/cardboard/cardboard_vr_device_provider.cc",
       "vr/android/cardboard/cardboard_vr_device_provider.h",
     ]
   }
 }