Run task queue manager work in batches

content/renderer/scheduler/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 "content/renderer/scheduler/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_argument.h"
 #include "base/message_loop/message_loop_proxy.h"
@@ skipping 25 matching lines @@
   end_idle_period_closure_ = base::Bind(&RendererSchedulerImpl::EndIdlePeriod,
                                         weak_renderer_scheduler_ptr_);
   idle_task_runner_ = make_scoped_refptr(new SingleThreadIdleTaskRunner(
       task_queue_manager_->TaskRunnerForQueue(IDLE_TASK_QUEUE),
       base::Bind(&RendererSchedulerImpl::CurrentIdleTaskDeadlineCallback,
                  weak_renderer_scheduler_ptr_)));
   renderer_task_queue_selector_->SetQueuePriority(
       CONTROL_TASK_QUEUE, RendererTaskQueueSelector::CONTROL_PRIORITY);
   renderer_task_queue_selector_->DisableQueue(IDLE_TASK_QUEUE);
   task_queue_manager_->SetAutoPump(IDLE_TASK_QUEUE, false);
+  // See crbug.com/444764 for how this work batch size was derived.
+  task_queue_manager_->SetWorkBatchSize(4);
 
   for (size_t i = 0; i < TASK_QUEUE_COUNT; i++) {
     task_queue_manager_->SetQueueName(
         i, TaskQueueIdToString(static_cast<QueueId>(i)));
   }
   TRACE_EVENT_OBJECT_CREATED_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"), "RendererScheduler",
       this);
 }
 
@@ skipping 176 matching lines @@
   task_queue_manager_->PumpQueue(IDLE_TASK_QUEUE);
 }
 
 void RendererSchedulerImpl::EndIdlePeriod() {
   TRACE_EVENT_ASYNC_END0(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                          "RendererSchedulerIdlePeriod", this);
   main_thread_checker_.CalledOnValidThread();
   renderer_task_queue_selector_->DisableQueue(IDLE_TASK_QUEUE);
 }
 
+void RendererSchedulerImpl::SetTimeSourceForTesting(
+    scoped_refptr<cc::TestNowSource> time_source) {
+  main_thread_checker_.CalledOnValidThread();
+  time_source_ = time_source;
+  task_queue_manager_->SetTimeSourceForTesting(time_source);
+}
+
 base::TimeTicks RendererSchedulerImpl::Now() const {
-  return gfx::FrameTime::Now();
+  return UNLIKELY(time_source_) ? time_source_->Now() : base::TimeTicks::Now();
 }
 
 RendererSchedulerImpl::PollableNeedsUpdateFlag::PollableNeedsUpdateFlag(
     base::Lock* write_lock_)
     : flag_(false), write_lock_(write_lock_) {
 }
 
 RendererSchedulerImpl::PollableNeedsUpdateFlag::~PollableNeedsUpdateFlag() {
 }
 
@@ skipping 52 matching lines @@
   state->SetDouble("last_input_time",
                    (last_input_time_ - base::TimeTicks()).InMillisecondsF());
   state->SetDouble(
       "estimated_next_frame_begin",
       (estimated_next_frame_begin_ - base::TimeTicks()).InMillisecondsF());
 
   return state;
 }
 
 }  // namespace content