Update from https://crrev.com/314320

cc/resources/pixel_buffer_tile_task_worker_pool.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/resources/pixel_buffer_tile_task_worker_pool.h"
 
 #include <algorithm>
 
 #include "base/containers/stack_container.h"
 #include "base/strings/stringprintf.h"
@@ skipping 570 matching lines @@
     // from being scheduled.
     if (!did_throttle_raster_tasks[task_set] &&
         should_notify_client_if_no_tasks_are_pending_[task_set]) {
       new_task_set_finished_tasks[task_set] = CreateTaskSetFinishedTask(
           task_runner_.get(),
           base::Bind(&PixelBufferTileTaskWorkerPool::OnTaskSetFinished,
                      task_set_finished_weak_ptr_factory_.GetWeakPtr(),
                      task_set));
       task_set_finished_tasks_pending_[task_set] = true;
       InsertNodeForTask(&graph_, new_task_set_finished_tasks[task_set].get(),
-                        kTaskSetFinishedTaskPriority,
+                        kTaskSetFinishedTaskPriorityBase + task_set,
                         scheduled_task_counts[task_set]);
       for (RasterTaskVector::ContainerType::const_iterator it =
                tasks[task_set].container().begin();
            it != tasks[task_set].container().end(); ++it) {
         graph_.edges.push_back(
             TaskGraph::Edge(*it, new_task_set_finished_tasks[task_set].get()));
       }
     }
   }
 
@@ skipping 119 matching lines @@
 void PixelBufferTileTaskWorkerPool::ThrottleStateAsValueInto(
     base::debug::TracedValue* throttle_state) const {
   throttle_state->SetInteger("bytes_available_for_upload",
                              max_bytes_pending_upload_ - bytes_pending_upload_);
   throttle_state->SetInteger("bytes_pending_upload", bytes_pending_upload_);
   throttle_state->SetInteger("scheduled_raster_task_count",
                              scheduled_raster_task_count_);
 }
 
 }  // namespace cc