[DO NOT COMMIT] Set ServiceWorker initiated task highest priority

third_party/WebKit/Source/platform/scheduler/renderer/web_frame_scheduler_impl.cc

Index: third_party/WebKit/Source/platform/scheduler/renderer/web_frame_scheduler_impl.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/web_frame_scheduler_impl.cc b/third_party/WebKit/Source/platform/scheduler/renderer/web_frame_scheduler_impl.cc
index 027e3b7aff4f969f4686bc6cad611023eda2f663..a17dcf492c0d3518b75cdf95f29ae9cfbb653d5b 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/web_frame_scheduler_impl.cc
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/web_frame_scheduler_impl.cc
@@ -224,6 +224,15 @@ void WebFrameSchedulerImpl::onFirstMeaningfulPaint() {
   renderer_scheduler_->OnFirstMeaningfulPaint();
 }
 
+void WebFrameSchedulerImpl::setMaximumPriorityForLabTest() {
+  loadingTaskRunner();
+  loading_task_queue_->SetQueuePriority(TaskQueue::CONTROL_PRIORITY);
+  timerTaskRunner();
+  timer_task_queue_->SetQueuePriority(TaskQueue::CONTROL_PRIORITY);
+  unthrottledTaskRunner();
+  unthrottled_task_queue_->SetQueuePriority(TaskQueue::CONTROL_PRIORITY);
+}
+
 bool WebFrameSchedulerImpl::ShouldThrottleTimers() const {
   if (page_throttled_)
     return true;