Reland "Throttle resource message requests during user interaction"

content/renderer/scheduler/renderer_scheduler_impl.cc

Index: content/renderer/scheduler/renderer_scheduler_impl.cc
diff --git a/content/renderer/scheduler/renderer_scheduler_impl.cc b/content/renderer/scheduler/renderer_scheduler_impl.cc
index 7f006144fda6759d20b349cf7ce9c70627c0ace2..00f39c2ebd5850bebf4c16bef3a93ef6dbac3ee5 100644
--- a/content/renderer/scheduler/renderer_scheduler_impl.cc
+++ b/content/renderer/scheduler/renderer_scheduler_impl.cc
@@ -145,6 +145,15 @@ void RendererSchedulerImpl::UpdateForInputEvent() {
   last_input_time_ = Now();
 }
 
+bool RendererSchedulerImpl::IsHighPriorityWorkAnticipated() {
+  main_thread_checker_.CalledOnValidThread();

[davidben, 2015/02/03 19:46:47]

DCHECK(....);

Ditto for all the other instances of this call apparently. :-) I don't think
base::ThreadChecker::CalledOnValidThread aborts on its own. It just returns a
boolean.

https://code.google.com/p/chromium/codesearch#chromium/src/base/threading/thr...

[jdduke (slow), 2015/02/04 01:39:50]

Hah, good catch.

+  if (!task_queue_manager_)
+    return false;
+
+  MaybeUpdatePolicy();
+  return SchedulerPolicy() == COMPOSITOR_PRIORITY_POLICY;
+}
+
 bool RendererSchedulerImpl::ShouldYieldForHighPriorityWork() {
   main_thread_checker_.CalledOnValidThread();
   if (!task_queue_manager_)
@@ -155,6 +164,8 @@ bool RendererSchedulerImpl::ShouldYieldForHighPriorityWork() {
   // work outstanding. Note: even though the control queue is higher priority
   // we don't yield for it since these tasks are not user-provided work and they
   // are only intended to run before the next task, not interrupt the tasks.
+  // Note: This function could conceivable be implemented in terms of

[davidben, 2015/02/03 19:46:47]

Nit: conceivable -> conceivably

[jdduke (slow), 2015/02/04 01:39:50]

Done.

+  // |IsHighPriorityWorkAnticipated|, but for clarity is not.
   return SchedulerPolicy() == COMPOSITOR_PRIORITY_POLICY &&
          !task_queue_manager_->IsQueueEmpty(COMPOSITOR_TASK_QUEUE);
 }