Revert of TaskGraphRunner Group support

cc/tiles/tile_manager.cc

 // Copyright 2012 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/tiles/tile_manager.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
@@ skipping 153 matching lines @@
 size_t kTileTaskPriorityBase = 10u;
 
 void InsertNodeForTask(TaskGraph* graph,
                        TileTask* task,
                        size_t priority,
                        size_t dependencies) {
   DCHECK(std::find_if(graph->nodes.begin(), graph->nodes.end(),
                       [task](const TaskGraph::Node& node) {
                         return node.task == task;
                       }) == graph->nodes.end());
-
-  // TODO(ericrk): Add in more logic around category selection.
-  graph->nodes.push_back(
-      TaskGraph::Node(task, 0 /* category */, priority, dependencies));
+  graph->nodes.push_back(TaskGraph::Node(task, priority, dependencies));
 }
 
 void InsertNodesForRasterTask(TaskGraph* graph,
                               RasterTask* raster_task,
                               const ImageDecodeTask::Vector& decode_tasks,
                               size_t priority) {
   size_t dependencies = 0u;
 
   // Insert image decode tasks.
   for (ImageDecodeTask::Vector::const_iterator it = decode_tasks.begin();
@@ skipping 979 matching lines @@
 void TileManager::Signals::reset() {
   ready_to_activate = false;
   did_notify_ready_to_activate = false;
   ready_to_draw = false;
   did_notify_ready_to_draw = false;
   all_tile_tasks_completed = false;
   did_notify_all_tile_tasks_completed = false;
 }
 
 }  // namespace cc