diff -r 000000000000 -r 6474c204b198 gfx/layers/client/ClientTiledThebesLayer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/client/ClientTiledThebesLayer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,98 @@
+/* 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_CLIENTTILEDTHEBESLAYER_H
+#define GFX_CLIENTTILEDTHEBESLAYER_H
+
+#include "ClientLayerManager.h"         // for ClientLayer, etc
+#include "Layers.h"                     // for ThebesLayer, etc
+#include "mozilla/RefPtr.h"             // for RefPtr
+#include "mozilla/layers/TiledContentClient.h"
+#include "nsDebug.h"                    // for NS_RUNTIMEABORT
+#include "nsRegion.h"                   // for nsIntRegion
+
+class gfxContext;
+
+namespace mozilla {
+namespace layers {
+
+class ShadowableLayer;
+class SpecificLayerAttributes;
+
+/**
+ * An implementation of ThebesLayer that ONLY supports remote
+ * composition that is backed by tiles. This thebes layer implementation
+ * is better suited to mobile hardware to work around slow implementation
+ * of glTexImage2D (for OGL compositors), and restrait memory bandwidth.
+ *
+ * Tiled Thebes layers use a different protocol compared with other
+ * layers. A copy of the tiled buffer is made and sent to the compositing
+ * thread via the layers protocol. Tiles are uploaded by the buffers
+ * asynchonously without using IPC, that means they are not safe for cross-
+ * process use (bug 747811). Each tile has a TextureHost/Client pair but
+ * they communicate directly rather than using the Texture protocol.
+ *
+ * There is no ContentClient for tiled layers. There is a ContentHost, however.
+ */
+class ClientTiledThebesLayer : public ThebesLayer,
+                               public ClientLayer
+{
+  typedef ThebesLayer Base;
+
+public:
+  ClientTiledThebesLayer(ClientLayerManager* const aManager);
+  ~ClientTiledThebesLayer();
+
+  // Override name to distinguish it from ClientThebesLayer in layer dumps
+  virtual const char* Name() const { return "TiledThebesLayer"; }
+
+  // Thebes Layer
+  virtual Layer* AsLayer() { return this; }
+  virtual void InvalidateRegion(const nsIntRegion& aRegion) {
+    mInvalidRegion.Or(mInvalidRegion, aRegion);
+    mValidRegion.Sub(mValidRegion, aRegion);
+    mLowPrecisionValidRegion.Sub(mLowPrecisionValidRegion, aRegion);
+  }
+
+  // Shadow methods
+  virtual void FillSpecificAttributes(SpecificLayerAttributes& aAttrs);
+  virtual ShadowableLayer* AsShadowableLayer() { return this; }
+
+  virtual void Disconnect()
+  {
+    ClientLayer::Disconnect();
+  }
+
+  virtual void RenderLayer();
+
+  virtual void ClearCachedResources() MOZ_OVERRIDE;
+
+private:
+  ClientLayerManager* ClientManager()
+  {
+    return static_cast<ClientLayerManager*>(mManager);
+  }
+
+  /**
+   * For the initial PaintThebes of a transaction, calculates all the data
+   * needed for that paint and any repeated transactions.
+   */
+  void BeginPaint();
+
+  /**
+   * When a paint ends, updates any data necessary to persist until the next
+   * paint. If aFinish is true, this will cause the paint to be marked as
+   * finished.
+   */
+  void EndPaint(bool aFinish);
+
+  RefPtr<TiledContentClient> mContentClient;
+  nsIntRegion mLowPrecisionValidRegion;
+  BasicTiledLayerPaintData mPaintData;
+};
+
+} // layers
+} // mozilla
+
+#endif