diff -r 000000000000 -r 6474c204b198 gfx/layers/basic/BasicThebesLayer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/basic/BasicThebesLayer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,130 @@
+/* -*- 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/. */
+
+#ifndef GFX_BASICTHEBESLAYER_H
+#define GFX_BASICTHEBESLAYER_H
+
+#include "Layers.h"                     // for ThebesLayer, LayerManager, etc
+#include "RotatedBuffer.h"              // for RotatedContentBuffer, etc
+#include "BasicImplData.h"              // for BasicImplData
+#include "BasicLayers.h"                // for BasicLayerManager
+#include "gfxPoint.h"                   // for gfxPoint
+#include "mozilla/RefPtr.h"             // for RefPtr
+#include "mozilla/gfx/BasePoint.h"      // for BasePoint
+#include "mozilla/layers/ContentClient.h"  // for ContentClientBasic
+#include "mozilla/mozalloc.h"           // for operator delete
+#include "nsDebug.h"                    // for NS_ASSERTION
+#include "nsISupportsImpl.h"            // for MOZ_COUNT_CTOR, etc
+#include "nsRegion.h"                   // for nsIntRegion
+class gfxContext;
+
+namespace mozilla {
+namespace layers {
+
+class ReadbackProcessor;
+
+class BasicThebesLayer : public ThebesLayer, public BasicImplData {
+public:
+  typedef RotatedContentBuffer::PaintState PaintState;
+  typedef RotatedContentBuffer::ContentType ContentType;
+
+  BasicThebesLayer(BasicLayerManager* aLayerManager) :
+    ThebesLayer(aLayerManager,
+                static_cast<BasicImplData*>(MOZ_THIS_IN_INITIALIZER_LIST())),
+    mContentClient(nullptr)
+  {
+    MOZ_COUNT_CTOR(BasicThebesLayer);
+  }
+  virtual ~BasicThebesLayer()
+  {
+    MOZ_COUNT_DTOR(BasicThebesLayer);
+  }
+
+  virtual void SetVisibleRegion(const nsIntRegion& aRegion)
+  {
+    NS_ASSERTION(BasicManager()->InConstruction(),
+                 "Can only set properties in construction phase");
+    ThebesLayer::SetVisibleRegion(aRegion);
+  }
+  virtual void InvalidateRegion(const nsIntRegion& aRegion)
+  {
+    NS_ASSERTION(BasicManager()->InConstruction(),
+                 "Can only set properties in construction phase");
+    mInvalidRegion.Or(mInvalidRegion, aRegion);
+    mInvalidRegion.SimplifyOutward(20);
+    mValidRegion.Sub(mValidRegion, mInvalidRegion);
+  }
+
+  virtual void PaintThebes(gfxContext* aContext,
+                           Layer* aMaskLayer,
+                           LayerManager::DrawThebesLayerCallback aCallback,
+                           void* aCallbackData,
+                           ReadbackProcessor* aReadback);
+
+  virtual void Validate(LayerManager::DrawThebesLayerCallback aCallback,
+                        void* aCallbackData) MOZ_OVERRIDE;
+
+  virtual void ClearCachedResources()
+  {
+    if (mContentClient) {
+      mContentClient->Clear();
+    }
+    mValidRegion.SetEmpty();
+  }
+
+  virtual void ComputeEffectiveTransforms(const gfx::Matrix4x4& aTransformToSurface)
+  {
+    if (!BasicManager()->IsRetained()) {
+      // Don't do any snapping of our transform, since we're just going to
+      // draw straight through without intermediate buffers.
+      mEffectiveTransform = GetLocalTransform() * aTransformToSurface;
+      if (gfxPoint(0,0) != mResidualTranslation) {
+        mResidualTranslation = gfxPoint(0,0);
+        mValidRegion.SetEmpty();
+      }
+      ComputeEffectiveTransformForMaskLayer(aTransformToSurface);
+      return;
+    }
+    ThebesLayer::ComputeEffectiveTransforms(aTransformToSurface);
+  }
+
+  BasicLayerManager* BasicManager()
+  {
+    return static_cast<BasicLayerManager*>(mManager);
+  }
+
+protected:
+  virtual void
+  PaintBuffer(gfxContext* aContext,
+              const nsIntRegion& aRegionToDraw,
+              const nsIntRegion& aExtendedRegionToDraw,
+              const nsIntRegion& aRegionToInvalidate,
+              bool aDidSelfCopy,
+              DrawRegionClip aClip,
+              LayerManager::DrawThebesLayerCallback aCallback,
+              void* aCallbackData)
+  {
+    if (!aCallback) {
+      BasicManager()->SetTransactionIncomplete();
+      return;
+    }
+    aCallback(this, aContext, aExtendedRegionToDraw, aClip,
+              aRegionToInvalidate, aCallbackData);
+    // Everything that's visible has been validated. Do this instead of just
+    // OR-ing with aRegionToDraw, since that can lead to a very complex region
+    // here (OR doesn't automatically simplify to the simplest possible
+    // representation of a region.)
+    nsIntRegion tmp;
+    tmp.Or(mVisibleRegion, aExtendedRegionToDraw);
+    mValidRegion.Or(mValidRegion, tmp);
+  }
+
+  RefPtr<ContentClientBasic> mContentClient;
+};
+
+}
+}
+
+#endif