Aura on Android: Idle monitor stub implementation

ui/base/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/compiler/compiler.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 if (is_android) {
@@ skipping 109 matching lines @@
     "dragdrop/drop_target_win.h",
     "dragdrop/os_exchange_data.cc",
     "dragdrop/os_exchange_data.h",
     "dragdrop/os_exchange_data_provider_mac.h",
     "dragdrop/os_exchange_data_provider_mac.mm",
     "dragdrop/os_exchange_data_provider_win.cc",
     "dragdrop/os_exchange_data_provider_win.h",
     "hit_test.h",
     "idle/idle.cc",
     "idle/idle.h",
+    "idle/idle_android.cc",
     "idle/idle_chromeos.cc",
     "idle/idle_linux.cc",
     "idle/idle_mac.mm",
     "idle/idle_win.cc",
     "ios/cru_context_menu_controller.h",
     "ios/cru_context_menu_controller.mm",
     "ios/cru_context_menu_holder.h",
     "ios/cru_context_menu_holder.mm",
     "l10n/formatter.cc",
     "l10n/formatter.h",
@@ skipping 423 matching lines @@
   if (use_aura) {
     if (use_x11) {
       sources += [ "clipboard/clipboard_aurax11.cc" ]
     } else if (!is_win && !is_android) {
       # This file is used for all non-X11, non-Windows, non-Android aura Builds.
       sources += [ "clipboard/clipboard_aura.cc" ]
     }
   }
 
   if (is_android || is_ios) {
+    sources -= [ "device_form_factor_desktop.cc" ]
+  }
+
+  if ((is_android && !use_aura) || is_ios) {
     sources -= [
-      "device_form_factor_desktop.cc",
       "idle/idle.cc",
       "idle/idle.h",
+      "idle/idle_android.cc",
     ]
   }
 }
 
 source_set("test_support") {
   testonly = true
   sources = [
     "test/material_design_controller_test_api.cc",
     "test/material_design_controller_test_api.h",
     "test/ui_controls.h",
@@ skipping 291 matching lines @@
   }
   if (is_mac) {
     data += [ "$root_out_dir/ui_unittests Framework.framework/" ]
 
     if (is_asan && symbol_level == 0) {
       data += [ "$root_out_dir/ui_base_unittests.dSYM/" ]
     }
   }
 }
 # TODO(GYP) Mac (ui_base_tests_bundle)