diff -r 000000000000 -r 6474c204b198 gfx/layers/RenderTrace.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/RenderTrace.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This is a general tool that will let you visualize platform operation.
+// Currently used for the layer system, the general syntax allows this
+// tools to be adapted to trace other operations.
+//
+// For the front end see: https://github.com/staktrace/rendertrace
+
+// Uncomment this line to enable RENDERTRACE
+//#define MOZ_RENDERTRACE
+
+#ifndef GFX_RENDERTRACE_H
+#define GFX_RENDERTRACE_H
+
+#include "gfx3DMatrix.h"
+#include "nsRect.h"
+
+namespace mozilla {
+namespace layers {
+
+class Layer;
+
+void RenderTraceLayers(Layer *aLayer, const char *aColor, const gfx3DMatrix aRootTransform = gfx3DMatrix(), bool aReset = true);
+
+void RenderTraceInvalidateStart(Layer *aLayer, const char *aColor, const nsIntRect aRect);
+void RenderTraceInvalidateEnd(Layer *aLayer, const char *aColor);
+
+void renderTraceEventStart(const char *aComment, const char *aColor);
+void renderTraceEventEnd(const char *aComment, const char *aColor);
+void renderTraceEventEnd(const char *aColor);
+
+struct RenderTraceScope {
+public:
+  RenderTraceScope(const char *aComment, const char *aColor)
+    : mComment(aComment)
+    , mColor(aColor)
+  {
+    renderTraceEventStart(mComment, mColor);
+  }
+  ~RenderTraceScope() {
+    renderTraceEventEnd(mComment, mColor);
+  }
+private:
+  const char *mComment;
+  const char *mColor;
+};
+
+#ifndef MOZ_RENDERTRACE
+inline void RenderTraceLayers(Layer *aLayer, const char *aColor, const gfx3DMatrix aRootTransform, bool aReset)
+{}
+
+inline void RenderTraceInvalidateStart(Layer *aLayer, const char *aColor, const nsIntRect aRect)
+{}
+
+inline void RenderTraceInvalidateEnd(Layer *aLayer, const char *aColor)
+{}
+
+inline void renderTraceEventStart(const char *aComment, const char *aColor)
+{}
+
+inline void renderTraceEventEnd(const char *aComment, const char *aColor)
+{}
+
+inline void renderTraceEventEnd(const char *aColor)
+{}
+
+#endif // MOZ_RENDERTRACE
+
+}
+}
+
+#endif //GFX_RENDERTRACE_H