Move RenderStats enumeration out of gpu_benchmarking_extension.

content/common/gpu/gpu_rendering_stats.h

 // Copyright (c) 2012 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 CONTENT_COMMON_GPU_GPU_RENDERING_STATS_H_
 #define CONTENT_COMMON_GPU_GPU_RENDERING_STATS_H_
 
 #include "base/time.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
 struct CONTENT_EXPORT GpuRenderingStats {
   GpuRenderingStats();
   ~GpuRenderingStats();
 
   int global_texture_upload_count;
   base::TimeDelta global_total_texture_upload_time;
   int texture_upload_count;
   base::TimeDelta total_texture_upload_time;
   base::TimeDelta global_total_processing_commands_time;
   base::TimeDelta total_processing_commands_time;
+  // Note: when adding new members, please remember to update enumerateFields
+  // in gpu_rendering_stats.cc.
+
+  // In conjunction with enumerateFields, this allows the embedder to
+  // enumerate the values in this structure without
+  // having to embed references to its specific member variables. This
+  // simplifies the addition of new fields to this type.
+  class Enumerator {
+  public:
+    virtual void addInt(const char* name, int value) = 0;

[piman, 2012/11/28 23:23:17]

nit: chrome style for function names

+    virtual void addTimeDeltaInSecondsF(const char* name,
+                                        const base::TimeDelta& value) = 0;
+
+  protected:
+    virtual ~Enumerator() { }
+  };
+
+  // Outputs the fields in this structure to the provided enumerator.
+  void enumerateFields(Enumerator* enumerator) const;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_RENDERING_STATS_H_