cc:: Add RenderingStatsInstrumentation to manage collection of RenderingStats

cc/debug/rendering_stats_instrumentation.h

Index: cc/debug/rendering_stats_instrumentation.h
diff --git a/cc/debug/rendering_stats_instrumentation.h b/cc/debug/rendering_stats_instrumentation.h
new file mode 100644
index 0000000000000000000000000000000000000000..b601f8dfa0c8b37faa2a4d9baf78feb3be30c8d0
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+++ b/cc/debug/rendering_stats_instrumentation.h
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+// 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_RENDERING_STATS_INSTRUMENTATION_H_
+#define CC_RENDERING_STATS_INSTRUMENTATION_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/synchronization/lock.h"
+#include "cc/debug/rendering_stats.h"
+
+namespace cc {
+
+// RenderingStatsInstrumentation is shared among threads and manages conditional
+// recording of rendering stats into a private RenderingStats instance.
+class CC_EXPORT RenderingStatsInstrumentation {
+ public:
+  static scoped_ptr<RenderingStatsInstrumentation> Create();
+
+  RenderingStats GetRenderingStats();
+
+  // Read and write access to the record_rendering_stats_ flag is not locked to
+  // improve performance. The flag is commonly turned off and hardly changes
+  // it's value during runtime.
+  bool record_rendering_stats() const { return record_rendering_stats_; }
+  void set_record_rendering_stats(bool record_rendering_stats) {
+    if (record_rendering_stats_ != record_rendering_stats)
+      record_rendering_stats_ = record_rendering_stats;
+  }
+
+  base::TimeTicks StartRecording() const;
+  base::TimeDelta EndRecording(base::TimeTicks start_time) const;
+
+  // TODO(egraether): Remove after switching Layer::update() to use this class.
+  // Used in LayerTreeHost::paintLayerContents().
+  void AddStats(const RenderingStats& other);
+
+  void IncrementAnimationFrameCount();
+  void SetScreenFrameCount(int64 count);
+  void SetDroppedFrameCount(int64 count);
+
+  void AddCommit(base::TimeDelta duration);
+  void AddPaint(base::TimeDelta duration, int64 pixels);
+  void AddRaster(base::TimeDelta duration,
+                 int64 pixels,
+                 bool is_in_pending_tree_now_bin);
+
+  void IncrementImplThreadScrolls();
+  void IncrementMainThreadScrolls();
+
+  void AddLayersDrawn(int64 amount);
+  void AddMissingTiles(int64 amount);
+
+  void AddDeferredImageDecode(base::TimeDelta duration);
+  void AddImageGathering(base::TimeDelta duration);
+
+  void IncrementDeferredImageCacheHitCount();
+
+ private:
+  RenderingStatsInstrumentation();
+
+  RenderingStats rendering_stats_;
+  bool record_rendering_stats_;
+
+  base::Lock lock_;
+
+  DISALLOW_COPY_AND_ASSIGN(RenderingStatsInstrumentation);
+};
+
+}  // namespace cc
+
+#endif  // CC_RENDERING_STATS_INSTRUMENTATION_H_