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

components/scheduler/renderer/web_frame_host_scheduler_impl_unittest.cc

Index: components/scheduler/renderer/web_frame_host_scheduler_impl_unittest.cc
diff --git a/components/scheduler/renderer/web_frame_host_scheduler_impl_unittest.cc b/components/scheduler/renderer/web_frame_host_scheduler_impl_unittest.cc
index 81defdff0ce094a3d625f3409448ee77138ee741..a87a4305fcbd6d04f6817ee997a77a2fa4777811 100644
--- a/components/scheduler/renderer/web_frame_host_scheduler_impl_unittest.cc
+++ b/components/scheduler/renderer/web_frame_host_scheduler_impl_unittest.cc
@@ -8,6 +8,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
+#include "components/scheduler/base/test_time_source.h"
 #include "components/scheduler/child/scheduler_task_runner_delegate_for_test.h"
 #include "components/scheduler/renderer/renderer_scheduler_impl.h"
 #include "components/scheduler/renderer/web_frame_scheduler_impl.h"
@@ -25,9 +26,10 @@ class WebFrameHostSchedulerImplTest : public testing::Test {
     clock_->Advance(base::TimeDelta::FromMicroseconds(5000));
     mock_task_runner_ = make_scoped_refptr(
         new cc::OrderedSimpleTaskRunner(clock_.get(), false));
-    main_task_runner_ =
-        SchedulerTaskRunnerDelegateForTest::Create(mock_task_runner_);
-    scheduler_.reset(new RendererSchedulerImpl(main_task_runner_));
+    main_task_runner_ = SchedulerTaskRunnerDelegateForTest::Create(
+        mock_task_runner_, make_scoped_ptr(new TestTimeSource(clock_.get())));
+    scheduler_.reset(new RendererSchedulerImpl(
+        main_task_runner_, RendererSchedulerImpl::TimeSource::NORMAL));
     frame_host_scheduler_.reset(
         new WebFrameHostSchedulerImpl(scheduler_.get()));
   }