scheduler: Move the Blink scheduler into Blink

components/scheduler/renderer/idle_time_estimator.cc

-// Copyright 2015 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/idle_time_estimator.h"
-
-#include "base/time/default_tick_clock.h"
-
-namespace scheduler {
-
-IdleTimeEstimator::IdleTimeEstimator(
-    const scoped_refptr<TaskQueue>& compositor_task_runner,
-    base::TickClock* time_source,
-    int sample_count,
-    double estimation_percentile)
-    : compositor_task_runner_(compositor_task_runner),
-      per_frame_compositor_task_runtime_(sample_count),
-      time_source_(time_source),
-      estimation_percentile_(estimation_percentile),
-      nesting_level_(0),
-      did_commit_(false) {
-  compositor_task_runner_->AddTaskObserver(this);
-}
-
-IdleTimeEstimator::~IdleTimeEstimator() {
-  compositor_task_runner_->RemoveTaskObserver(this);
-}
-
-base::TimeDelta IdleTimeEstimator::GetExpectedIdleDuration(
-    base::TimeDelta compositor_frame_interval) const {
-  base::TimeDelta expected_compositor_task_runtime_ =
-      per_frame_compositor_task_runtime_.Percentile(estimation_percentile_);
-  return std::max(base::TimeDelta(), compositor_frame_interval -
-                                         expected_compositor_task_runtime_);
-}
-
-void IdleTimeEstimator::DidCommitFrameToCompositor() {
-  // This will run inside of a WillProcessTask / DidProcessTask pair, let
-  // DidProcessTask know a frame was comitted.
-  if (nesting_level_ == 1)
-    did_commit_ = true;
-}
-
-void IdleTimeEstimator::Clear() {
-  task_start_time_ = base::TimeTicks();
-  prev_commit_time_ = base::TimeTicks();
-  cumulative_compositor_runtime_ = base::TimeDelta();
-  per_frame_compositor_task_runtime_.Clear();
-  did_commit_ = false;
-}
-
-void IdleTimeEstimator::WillProcessTask(const base::PendingTask& pending_task) {
-  nesting_level_++;
-  if (nesting_level_ == 1)
-    task_start_time_ = time_source_->NowTicks();
-}
-
-void IdleTimeEstimator::DidProcessTask(const base::PendingTask& pending_task) {
-  nesting_level_--;
-  DCHECK_GE(nesting_level_, 0);
-  if (nesting_level_ != 0)
-    return;
-
-  cumulative_compositor_runtime_ += time_source_->NowTicks() - task_start_time_;
-
-  if (did_commit_) {
-    per_frame_compositor_task_runtime_.InsertSample(
-        cumulative_compositor_runtime_);
-    cumulative_compositor_runtime_ = base::TimeDelta();
-    did_commit_ = false;
-  }
-}
-
-}  // namespace scheduler