tracing: Make ConvertableToTraceFormat move-only scoped_ptr

cc/raster/one_copy_tile_task_worker_pool.h

 // Copyright 2014 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_RASTER_ONE_COPY_TILE_TASK_WORKER_POOL_H_
 #define CC_RASTER_ONE_COPY_TILE_TASK_WORKER_POOL_H_
 
 #include <stdint.h>
 
 #include <deque>
@@ skipping 111 matching lines @@
   void RemoveStagingBuffer(const StagingBuffer* staging_buffer);
   void MarkStagingBufferAsFree(const StagingBuffer* staging_buffer);
   void MarkStagingBufferAsBusy(const StagingBuffer* staging_buffer);
   scoped_ptr<StagingBuffer> AcquireStagingBuffer(const Resource* resource,
                                                  uint64_t previous_content_id);
   base::TimeTicks GetUsageTimeForLRUBuffer();
   void ScheduleReduceMemoryUsage();
   void ReduceMemoryUsage();
   void ReleaseBuffersNotUsedSince(base::TimeTicks time);
 
-  scoped_refptr<base::trace_event::ConvertableToTraceFormat> StateAsValue()
-      const;
+  scoped_ptr<base::trace_event::ConvertableToTraceFormat> StateAsValue() const;
   void StagingStateAsValueInto(
       base::trace_event::TracedValue* staging_state) const;
 
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
   TaskGraphRunner* task_graph_runner_;
   const NamespaceToken namespace_token_;
   ResourceProvider* const resource_provider_;
   const int max_bytes_per_copy_operation_;
   const bool use_partial_raster_;
 
@@ skipping 16 matching lines @@
   base::Closure reduce_memory_usage_callback_;
 
   base::WeakPtrFactory<OneCopyTileTaskWorkerPool> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OneCopyTileTaskWorkerPool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RASTER_ONE_COPY_TILE_TASK_WORKER_POOL_H_