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

components/scheduler/ppapi/webthread_impl_for_ppapi.cc

Index: components/scheduler/ppapi/webthread_impl_for_ppapi.cc
diff --git a/components/scheduler/ppapi/webthread_impl_for_ppapi.cc b/components/scheduler/ppapi/webthread_impl_for_ppapi.cc
index 113efdc4da63340f63ac3730a15d1b930e138b15..ffca25d48cd95fa88c76cdb77871cfb61e02a304 100644
--- a/components/scheduler/ppapi/webthread_impl_for_ppapi.cc
+++ b/components/scheduler/ppapi/webthread_impl_for_ppapi.cc
@@ -7,6 +7,7 @@
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
+#include "base/time/default_tick_clock.h"
 #include "components/scheduler/base/task_queue.h"
 #include "components/scheduler/child/scheduler_task_runner_delegate_impl.h"
 #include "components/scheduler/child/web_scheduler_impl.h"
@@ -18,7 +19,8 @@ namespace scheduler {
 WebThreadImplForPPAPI::WebThreadImplForPPAPI()
     : thread_id_(base::PlatformThread::CurrentId()),
       task_runner_delegate_(SchedulerTaskRunnerDelegateImpl::Create(
-          base::MessageLoop::current())),
+          base::MessageLoop::current(),
+          make_scoped_ptr(new base::DefaultTickClock()))),
       worker_scheduler_(WorkerScheduler::Create(task_runner_delegate_)) {
   worker_scheduler_->Init();
   task_runner_ = worker_scheduler_->DefaultTaskRunner();