Suspend more task queues for background renderers (experimental)

components/scheduler/renderer/renderer_scheduler_impl.cc

Index: components/scheduler/renderer/renderer_scheduler_impl.cc
diff --git a/components/scheduler/renderer/renderer_scheduler_impl.cc b/components/scheduler/renderer/renderer_scheduler_impl.cc
index 9936a69f9fa5b9489f626e9bc478d8b8048f80a0..a09d89dc0ee541b20460cf5e620519897704dd89 100644
--- a/components/scheduler/renderer/renderer_scheduler_impl.cc
+++ b/components/scheduler/renderer/renderer_scheduler_impl.cc
@@ -119,6 +119,7 @@ RendererSchedulerImpl::MainThreadOnly::MainThreadOnly(
       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),
@@ -832,6 +833,11 @@ void RendererSchedulerImpl::UpdatePolicyLocked(UpdateType update_type) {
     new_policy.timer_queue_policy.is_enabled = false;
   }
 
+  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(
@@ -1214,6 +1220,7 @@ void RendererSchedulerImpl::SuspendTimerQueueWhenBackgrounded() {
     return;
 
   MainThreadOnly().timer_queue_suspended_when_backgrounded = true;
+  MainThreadOnly().renderer_suspended = true;

[Sami, 2016/05/31 10:11:21]

I guess this is just for testing, but ultimately you'd want to do this in
RendererSchedulerImpl::SuspendRenderer().

[hajimehoshi, 2016/05/31 11:10:07]

Ah, this was my mistake: Setting this variable should be in SuspendRenderer as
you suggested. Done.

   ForceUpdatePolicy();
 }
 
@@ -1223,6 +1230,7 @@ void RendererSchedulerImpl::ResumeTimerQueueWhenForegrounded() {
     return;
 
   MainThreadOnly().timer_queue_suspended_when_backgrounded = false;
+  MainThreadOnly().renderer_suspended = false;
   ForceUpdatePolicy();
 }