cc: Prevent recursion in *TileTaskWorkerPool methods.

cc/resources/pixel_buffer_tile_task_worker_pool.h

 // 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.
 
 #ifndef CC_RESOURCES_PIXEL_BUFFER_TILE_TASK_WORKER_POOL_H_
 #define CC_RESOURCES_PIXEL_BUFFER_TILE_TASK_WORKER_POOL_H_
 
 #include <deque>
 #include <vector>
 
@@ skipping 78 matching lines @@
   void CheckForCompletedRasterTasks();
   void ScheduleMoreTasks();
   unsigned PendingRasterTaskCount() const;
   TaskSetCollection PendingTasks() const;
   void CheckForCompletedRasterizerTasks();
 
   const char* StateName() const;
   scoped_refptr<base::debug::ConvertableToTraceFormat> StateAsValue() const;
   void ThrottleStateAsValueInto(base::debug::TracedValue* throttle_state) const;
 
+  bool single_entry_holder;
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
   TaskGraphRunner* task_graph_runner_;
   const NamespaceToken namespace_token_;
   TileTaskRunnerClient* client_;
   ContextProvider* context_provider_;
   ResourceProvider* resource_provider_;
 
   bool shutdown_;
 
   TileTaskQueue raster_tasks_;
@@ skipping 22 matching lines @@
 
   base::WeakPtrFactory<PixelBufferTileTaskWorkerPool>
       task_set_finished_weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PixelBufferTileTaskWorkerPool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PIXEL_BUFFER_TILE_TASK_WORKER_POOL_H_