Suspend more task queues for background renderers (experimental)

components/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 "components/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 101 matching lines @@
       idle_time_estimator(compositor_task_runner,
                           time_source,
                           kShortIdlePeriodDurationSampleCount,
                           kShortIdlePeriodDurationPercentile),
       current_use_case(UseCase::NONE),
       timer_queue_suspend_count(0),
       navigation_task_expected_count(0),
       expensive_task_policy(ExpensiveTaskPolicy::RUN),
       renderer_hidden(false),
       renderer_backgrounded(false),
+      renderer_suspended(false),
       timer_queue_suspension_when_backgrounded_enabled(false),
       timer_queue_suspended_when_backgrounded(false),
       was_shutdown(false),
       loading_tasks_seem_expensive(false),
       timer_tasks_seem_expensive(false),
       touchstart_expected_soon(false),
       have_seen_a_begin_main_frame(false),
       have_reported_blocking_intervention_in_current_policy(false),
       have_reported_blocking_intervention_since_navigation(false),
       has_visible_render_widget_with_touch_handler(false),
@@ skipping 253 matching lines @@
 }
 
 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;
   suspend_timers_when_backgrounded_closure_.Cancel();
   ResumeTimerQueueWhenForegrounded();
 }
 
 void RendererSchedulerImpl::SuspendRenderer() {
   helper_.CheckOnValidThread();
   DCHECK(MainThreadOnly().renderer_backgrounded);
   if (helper_.IsShutdown())
     return;
   suspend_timers_when_backgrounded_closure_.Cancel();
   // TODO(hajimehoshi): We might need to suspend not only timer queue but also
   // e.g. loading tasks or postMessage.
+  MainThreadOnly().renderer_suspended = true;
   SuspendTimerQueueWhenBackgrounded();
 }
 
 void RendererSchedulerImpl::EndIdlePeriod() {
   if (MainThreadOnly().in_idle_period_for_testing)
     return;
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                "RendererSchedulerImpl::EndIdlePeriod");
   helper_.CheckOnValidThread();
   idle_helper_.EndIdlePeriod();
@@ skipping 417 matching lines @@
   }
 
   MainThreadOnly().expensive_task_policy = expensive_task_policy;
 
   if (MainThreadOnly().timer_queue_suspend_count != 0 ||
       MainThreadOnly().timer_queue_suspended_when_backgrounded) {
     new_policy.timer_queue_policy.is_enabled = false;
     new_policy.timer_queue_policy.time_domain_type = TimeDomainType::REAL;
   }
 
+  if (MainThreadOnly().renderer_suspended) {
+    new_policy.loading_queue_policy.is_enabled = false;
+    DCHECK(!new_policy.timer_queue_policy.is_enabled);
+  }
+
   // Tracing is done before the early out check, because it's quite possible we
   // will otherwise miss this information in traces.
   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"), "RendererScheduler",
       this, AsValueLocked(now));
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"), "use_case",
                  use_case);
   TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                  "touchstart_expected_soon",
                  MainThreadOnly().touchstart_expected_soon);
@@ skipping 480 matching lines @@
     BroadcastConsoleWarning(
         "Blink deferred a task in order to make scrolling smoother. "
         "Your timer and network tasks should take less than 50ms to run "
         "to avoid this. Please see "
         "https://developers.google.com/web/tools/chrome-devtools/profile/evaluate-performance/rail"
         " and https://crbug.com/574343#c40 for more information.");
   }
 }
 
 }  // namespace scheduler