cc: Add a resource_provider_ dcheck in resource_pool creation.

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <set>
@@ skipping 2073 matching lines @@
       is_synchronous_single_threaded_ ? std::numeric_limits<size_t>::max()
                                       : settings_.scheduled_raster_task_limit);
   UpdateTileManagerMemoryPolicy(ActualManagedMemoryPolicy());
 }
 
 void LayerTreeHostImpl::CreateResourceAndTileTaskWorkerPool(
     scoped_ptr<TileTaskWorkerPool>* tile_task_worker_pool,
     scoped_ptr<ResourcePool>* resource_pool,
     scoped_ptr<ResourcePool>* staging_resource_pool) {
   DCHECK(GetTaskRunner());
+  // TODO(vmpstr): Make this a DCHECK (or remove) when crbug.com/419086 is
+  // resolved.
+  CHECK(resource_provider_);
 
   // Pass the single-threaded synchronous task graph runner to the worker pool
   // if we're in synchronous single-threaded mode.
   TaskGraphRunner* task_graph_runner = task_graph_runner_;
   if (is_synchronous_single_threaded_) {
     DCHECK(!single_thread_synchronous_task_graph_runner_);
     single_thread_synchronous_task_graph_runner_.reset(new TaskGraphRunner);
     task_graph_runner = single_thread_synchronous_task_graph_runner_.get();
   }
 
@@ skipping 1503 matching lines @@
   if (active_tree()) {
     LayerAnimationValueProvider* layer = active_tree()->LayerById(layer_id);
     if (layer)
       return layer->ScrollOffsetForAnimation();
   }
 
   return gfx::ScrollOffset();
 }
 
 }  // namespace cc