Don't include the tracing in gpu_memory_buffer.h

cc/raster/staging_buffer_pool.h

 // Copyright 2016 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_STAGING_BUFFER_POOL_H_
 #define CC_RASTER_STAGING_BUFFER_POOL_H_
 
 #include <stdint.h>
 
 #include <deque>
 #include <memory>
 #include <set>
 
 #include "base/macros.h"
 #include "base/memory/memory_coordinator_client.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
 #include "base/trace_event/memory_dump_provider.h"
+#include "base/trace_event/trace_event.h"
 #include "cc/output/context_provider.h"
 #include "cc/resources/resource_provider.h"
 
 namespace gpu {
 namespace gles2 {
 class GLES2Interface;
 }
 }
 
 namespace cc {
@@ skipping 82 matching lines @@
   base::Closure reduce_memory_usage_callback_;
 
   base::WeakPtrFactory<StagingBufferPool> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(StagingBufferPool);
 };
 
 }  // namespace cc
 
 #endif  // CC_RASTER_STAGING_BUFFER_POOL_H_