diff -r 000000000000 -r 6474c204b198 gfx/layers/composite/ThebesLayerComposite.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/composite/ThebesLayerComposite.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,92 @@
+/* -*- Mode: C++; tab-width: 20; 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/. */
+
+#ifndef GFX_ThebesLayerComposite_H
+#define GFX_ThebesLayerComposite_H
+
+#include "Layers.h"                     // for Layer (ptr only), etc
+#include "gfxRect.h"                    // for gfxRect
+#include "mozilla/Attributes.h"         // for MOZ_OVERRIDE
+#include "mozilla/RefPtr.h"             // for RefPtr
+#include "mozilla/layers/LayerManagerComposite.h"  // for LayerComposite, etc
+#include "mozilla/layers/LayersTypes.h"  // for LayerRenderState, etc
+#include "nsDebug.h"                    // for NS_RUNTIMEABORT
+#include "nsRegion.h"                   // for nsIntRegion
+#include "nscore.h"                     // for nsACString
+
+struct nsIntPoint;
+struct nsIntRect;
+
+
+namespace mozilla {
+namespace layers {
+
+/**
+ * Thebes layers use ContentHosts for their compsositable host.
+ * By using different ContentHosts, ThebesLayerComposite support tiled and
+ * non-tiled Thebes layers and single or double buffering.
+ */
+
+class CompositableHost;
+class ContentHost;
+class TiledLayerComposer;
+
+class ThebesLayerComposite : public ThebesLayer,
+                             public LayerComposite
+{
+public:
+  ThebesLayerComposite(LayerManagerComposite *aManager);
+  virtual ~ThebesLayerComposite();
+
+  virtual void Disconnect() MOZ_OVERRIDE;
+
+  virtual LayerRenderState GetRenderState() MOZ_OVERRIDE;
+
+  CompositableHost* GetCompositableHost() MOZ_OVERRIDE;
+
+  virtual void Destroy() MOZ_OVERRIDE;
+
+  virtual Layer* GetLayer() MOZ_OVERRIDE;
+
+  virtual TiledLayerComposer* GetTiledLayerComposer() MOZ_OVERRIDE;
+
+  virtual void RenderLayer(const nsIntRect& aClipRect) MOZ_OVERRIDE;
+
+  virtual void CleanupResources() MOZ_OVERRIDE;
+
+  virtual bool SetCompositableHost(CompositableHost* aHost) MOZ_OVERRIDE;
+
+  virtual LayerComposite* AsLayerComposite() MOZ_OVERRIDE { return this; }
+
+  void EnsureTiled() { mRequiresTiledProperties = true; }
+
+  virtual void InvalidateRegion(const nsIntRegion& aRegion)
+  {
+    NS_RUNTIMEABORT("ThebesLayerComposites can't fill invalidated regions");
+  }
+
+  void SetValidRegion(const nsIntRegion& aRegion)
+  {
+    MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) ValidRegion", this));
+    mValidRegion = aRegion;
+    Mutated();
+  }
+
+  MOZ_LAYER_DECL_NAME("ThebesLayerComposite", TYPE_THEBES)
+
+protected:
+
+  virtual nsACString& PrintInfo(nsACString& aTo, const char* aPrefix) MOZ_OVERRIDE;
+
+private:
+  CSSToScreenScale GetEffectiveResolution();
+
+  RefPtr<ContentHost> mBuffer;
+  bool mRequiresTiledProperties;
+};
+
+} /* layers */
+} /* mozilla */
+#endif /* GFX_ThebesLayerComposite_H */