Adds a flag to support "Virtual Time" to the blink scheduler

components/scheduler/BUILD.gn

 # Copyright 2015 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("//components/scheduler/scheduler.gni")
 
 # GYP version: components/scheduler.gypi:scheduler
 component("scheduler") {
   sources = rebase_path(scheduler_gypi_values.scheduler_sources,
                         ".",
                         "//components/scheduler")
 
   defines = [ "SCHEDULER_IMPLEMENTATION" ]
 
   # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   deps = [
+    ":common",
     "//base",
     "//cc:cc",
     "//third_party/WebKit/public:blink",
     "//ui/gfx:gfx",
   ]
 
   public_deps = [
     "//third_party/WebKit/public:blink",
   ]
 }
 
+# GYP version: components/scheduler.gypi:scheduler_common
+source_set("common") {
+  sources = rebase_path(scheduler_gypi_values.scheduler_common_sources,
+                        ".",
+                        "//components/scheduler")
+}
+
 source_set("unit_tests") {
   testonly = true
 
   sources = [
     "base/nestable_task_runner_for_test.cc",
     "base/nestable_task_runner_for_test.h",
     "base/task_queue_manager_unittest.cc",
     "base/task_queue_selector_unittest.cc",
     "base/task_queue_sets_unittest.cc",
     "base/test_always_fail_time_source.cc",
     "base/test_always_fail_time_source.h",
     "base/test_time_source.cc",
     "base/test_time_source.h",
     "child/idle_helper_unittest.cc",
     "child/scheduler_helper_unittest.cc",
     "child/scheduler_task_runner_delegate_for_test.cc",
     "child/scheduler_task_runner_delegate_for_test.h",
     "child/scheduler_task_runner_delegate_impl_unittest.cc",
+    "child/virtual_time_task_runner_delegate_unittest.cc",
     "child/webthread_impl_for_worker_scheduler_unittest.cc",
     "child/worker_scheduler_impl_unittest.cc",
     "renderer/deadline_task_runner_unittest.cc",
     "renderer/render_widget_signals_unittest.cpp",
     "renderer/renderer_scheduler_impl_unittest.cc",
     "renderer/task_cost_estimator_unittest.cc",
     "renderer/user_model_unittest.cc",
     "renderer/web_frame_host_scheduler_impl_unittest.cc",
     "renderer/webthread_impl_for_renderer_scheduler_unittest.cc",
   ]
 
   deps = [
     ":scheduler",
     "//cc:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
 
 # GYP version: components/scheduler.gypi:scheduler_test_support
 static_library("test_support") {
   sources = rebase_path(scheduler_gypi_values.scheduler_test_support_sources,
                         ".",
                         "//components/scheduler")
 
   deps = [
     "//base",
   ]
 }