cc: Simplify task and its derived classes.

cc/raster/task_graph_runner.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 "cc/raster/task_graph_runner.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/atomic_sequence_num.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/trace_event/trace_event.h"
 
 namespace cc {
 
-Task::Task() : will_run_(false), did_run_(false) {}
-
-Task::~Task() {
-  DCHECK(!will_run_);
-}
-
-void Task::WillRun() {
-  DCHECK(!will_run_);
-  DCHECK(!did_run_);
-  will_run_ = true;
-}
-
-void Task::DidRun() {
-  DCHECK(will_run_);
-  will_run_ = false;
-  did_run_ = true;
-}
-
-bool Task::HasFinishedRunning() const {
-  return did_run_;
-}
-
 TaskGraph::TaskGraph() {}
 
 TaskGraph::TaskGraph(const TaskGraph& other) = default;
 
 TaskGraph::~TaskGraph() {}
 
 void TaskGraph::Swap(TaskGraph* other) {
   nodes.swap(other->nodes);
   edges.swap(other->edges);
 }
 
 void TaskGraph::Reset() {
   nodes.clear();
   edges.clear();
 }
 
 }  // namespace cc