[scheduler] Throttle default timer queue when renderer is backgrounded.

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

 // Copyright 2014 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/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 469 matching lines @@
 
 void RendererSchedulerImpl::OnRendererBackgrounded() {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                "RendererSchedulerImpl::OnRendererBackgrounded");
   helper_.CheckOnValidThread();
   if (helper_.IsShutdown() || MainThreadOnly().renderer_backgrounded)
     return;
 
   MainThreadOnly().renderer_backgrounded = true;
 
+  UpdatePolicy();
+
   base::TimeTicks now = tick_clock()->NowTicks();
   MainThreadOnly().foreground_main_thread_load_tracker.Pause(now);
   MainThreadOnly().background_main_thread_load_tracker.Resume(now);
 
   if (!MainThreadOnly().timer_queue_suspension_when_backgrounded_enabled)
     return;
 
   suspend_timers_when_backgrounded_closure_.Cancel();
   base::TimeDelta suspend_timers_when_backgrounded_delay =
       base::TimeDelta::FromMilliseconds(
           kSuspendTimersWhenBackgroundedDelayMillis);
   control_task_runner_->PostDelayedTask(
       FROM_HERE, suspend_timers_when_backgrounded_closure_.callback(),
       suspend_timers_when_backgrounded_delay);
 }
 
 void RendererSchedulerImpl::OnRendererForegrounded() {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                "RendererSchedulerImpl::OnRendererForegrounded");
   helper_.CheckOnValidThread();
   if (helper_.IsShutdown() || !MainThreadOnly().renderer_backgrounded)
     return;
 
   MainThreadOnly().renderer_backgrounded = false;
   MainThreadOnly().renderer_suspended = false;
 
+  UpdatePolicy();
+
   base::TimeTicks now = tick_clock()->NowTicks();
   MainThreadOnly().foreground_main_thread_load_tracker.Resume(now);
   MainThreadOnly().background_main_thread_load_tracker.Pause(now);
 
   suspend_timers_when_backgrounded_closure_.Cancel();
   ResumeTimerQueueWhenForegroundedOrResumed();
 }
 
 void RendererSchedulerImpl::OnAudioStateChanged() {
   bool is_audio_playing = false;
@@ skipping 540 matching lines @@
         TimeDomainType::VIRTUAL;
     new_policy.default_queue_policy.time_domain_type = TimeDomainType::VIRTUAL;
     new_policy.loading_queue_policy.time_domain_type = TimeDomainType::VIRTUAL;
     new_policy.timer_queue_policy.time_domain_type = TimeDomainType::VIRTUAL;
   }
 
   new_policy.should_disable_throttling =
       ShouldDisableThrottlingBecauseOfAudio(now) ||
       MainThreadOnly().use_virtual_time;
 
+  // TODO(altimin): Consider adding default timer tq to background time
+  // budget pool.
+  if (MainThreadOnly().renderer_backgrounded)
+    new_policy.timer_queue_policy.time_domain_type = TimeDomainType::THROTTLED;
+
   // Tracing is done before the early out check, because it's quite possible we
   // will otherwise miss this information in traces.
   CreateTraceEventObjectSnapshotLocked();
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"), "use_case",
                  use_case);
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"), "rail_mode",
                  new_policy.rail_mode);
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                  "touchstart_expected_soon",
                  MainThreadOnly().touchstart_expected_soon);
@@ skipping 722 matching lines @@
     case TimeDomainType::VIRTUAL:
       return "virtual";
     default:
       NOTREACHED();
       return nullptr;
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink