Revert of cc: Remove WorkerPool class and instead use TaskGraphRunner directly.

cc/resources/picture_pile.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/resources/picture_pile.h"
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
 #include "cc/base/region.h"
 #include "cc/debug/rendering_stats_instrumentation.h"
 #include "cc/resources/picture_pile_impl.h"
-#include "cc/resources/raster_worker_pool.h"
 #include "cc/resources/tile_priority.h"
+#include "cc/resources/worker_pool.h"
 
 namespace {
 // Layout pixel buffer around the visible layer rect to record.  Any base
 // picture that intersects the visible layer rect expanded by this distance
 // will be recorded.
 const int kPixelDistanceToRecord = 8000;
 
 // TODO(humper): The density threshold here is somewhat arbitrary; need a
 // way to set // this from the command line so we can write a benchmark
 // script and find a sweet spot.
@@ skipping 199 matching lines @@
           std::numeric_limits<int64>::max());
       for (int i = 0; i < repeat_count; i++) {
         base::TimeTicks start_time = stats_instrumentation->StartRecording();
         picture->Record(painter, tile_grid_info_);
         base::TimeDelta duration =
             stats_instrumentation->EndRecording(start_time);
         best_duration = std::min(duration, best_duration);
       }
       int recorded_pixel_count =
           picture->LayerRect().width() * picture->LayerRect().height();
-      int num_raster_threads = RasterWorkerPool::GetNumRasterThreads();
+      int num_raster_threads = WorkerPool::GetNumRasterThreads();
       stats_instrumentation->AddRecord(best_duration, recorded_pixel_count);
       if (num_raster_threads > 1)
         picture->GatherPixelRefs(tile_grid_info_);
       picture->CloneForDrawing(num_raster_threads);
     }
 
     for (TilingData::Iterator it(&tiling_, record_rect);
         it; ++it) {
       const PictureMapKey& key = it.index();
       gfx::Rect tile = PaddedRect(key);
       if (record_rect.Contains(tile)) {
         PictureInfo& info = picture_map_[key];
         info.SetPicture(picture);
       }
     }
   }
 
   UpdateRecordedRegion();
   return true;
 }
 
 }  // namespace cc