[DO NOT COMMIT] Set ServiceWorker initiated task highest priority

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

 // 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.
 
 #include "platform/scheduler/renderer/web_frame_scheduler_impl.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/blame_context.h"
 #include "platform/scheduler/base/real_time_domain.h"
 #include "platform/scheduler/base/virtual_time_domain.h"
@@ skipping 206 matching lines @@
   if (loading_queue_enabled_voter_)
     loading_queue_enabled_voter_->SetQueueEnabled(!frame_suspended);
   if (timer_queue_enabled_voter_)
     timer_queue_enabled_voter_->SetQueueEnabled(!frame_suspended);
 }
 
 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;
   return RuntimeEnabledFeatures::timerThrottlingForHiddenFramesEnabled() &&
          !frame_visible_ && cross_origin_;
 }
 
 void WebFrameSchedulerImpl::UpdateTimerThrottling(bool was_throttled) {
   bool should_throttle = ShouldThrottleTimers();
   if (was_throttled == should_throttle || !timer_web_task_runner_)
     return;
   if (should_throttle) {
     renderer_scheduler_->task_queue_throttler()->IncreaseThrottleRefCount(
         timer_task_queue_.get());
   } else {
     renderer_scheduler_->task_queue_throttler()->DecreaseThrottleRefCount(
         timer_task_queue_.get());
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink