Revert of TaskGraphRunner Group support

cc/raster/tile_task_worker_pool_unittest.cc

 // Copyright 2013 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/tile_task_worker_pool.h"
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 176 matching lines @@
     tile_task_worker_pool_->AsTileTaskRunner()->CheckForCompletedTasks();
   }
 
   void ScheduleTasks() {
     graph_.Reset();
 
     size_t priority = 0;
 
     for (RasterTaskVector::const_iterator it = tasks_.begin();
          it != tasks_.end(); ++it) {
-      graph_.nodes.emplace_back(it->get(), 0 /* group */, priority++,
-                                0 /* dependencies */);
+      graph_.nodes.emplace_back(it->get(), priority++, 0 /* dependencies */);
     }
 
     tile_task_worker_pool_->AsTileTaskRunner()->ScheduleTasks(&graph_);
   }
 
   void AppendTask(unsigned id, const gfx::Size& size) {
     scoped_ptr<ScopedResource> resource(
         ScopedResource::Create(resource_provider_.get()));
     resource->Allocate(size, ResourceProvider::TEXTURE_HINT_IMMUTABLE,
                        RGBA_8888);
@@ skipping 160 matching lines @@
 
 INSTANTIATE_TEST_CASE_P(TileTaskWorkerPoolTests,
                         TileTaskWorkerPoolTest,
                         ::testing::Values(TILE_TASK_WORKER_POOL_TYPE_ZERO_COPY,
                                           TILE_TASK_WORKER_POOL_TYPE_ONE_COPY,
                                           TILE_TASK_WORKER_POOL_TYPE_GPU,
                                           TILE_TASK_WORKER_POOL_TYPE_BITMAP));
 
 }  // namespace
 }  // namespace cc