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diff --git a/gfx/layers/basic/BasicLayers.h b/gfx/layers/basic/BasicLayers.h
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+++ b/gfx/layers/basic/BasicLayers.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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_BASICLAYERS_H
+#define GFX_BASICLAYERS_H
+
+#include <stdint.h>  // for INT32_MAX, int32_t
+#include "gfxTypes.h"
+#include "gfxContext.h"                   // for gfxContext
+#include "mozilla/Attributes.h"           // for override
+#include "mozilla/WidgetUtils.h"          // for ScreenRotation
+#include "mozilla/layers/LayerManager.h"  // for LayerManager::DrawPaintedLayerCallback, LayerManager::END_DEFAULT, LayerManager::EndTra...
+#include "mozilla/layers/LayersTypes.h"   // for BufferMode, LayersBackend, etc
+#include "mozilla/TimeStamp.h"
+#include "nsAString.h"
+#include "nsCOMPtr.h"         // for already_AddRefed
+#include "nsISupportsImpl.h"  // for gfxContext::AddRef, etc
+#include "nsRegion.h"         // for nsIntRegion
+#include "nscore.h"           // for nsAString, etc
+
+class nsIWidget;
+
+namespace mozilla {
+namespace layers {
+
+class CanvasLayer;
+class ColorLayer;
+class ContainerLayer;
+class ImageFactory;
+class ImageLayer;
+class Layer;
+class PaintLayerContext;
+class PaintedLayer;
+class ReadbackLayer;
+
+/**
+ * This is a cairo/Thebes-only, main-thread-only implementation of layers.
+ *
+ * In each transaction, the client sets up the layer tree and then during
+ * the drawing phase, each PaintedLayer is painted directly into the target
+ * context (with appropriate clipping and Push/PopGroups performed
+ * between layers).
+ */
+class BasicLayerManager final : public LayerManager {
+ public:
+  enum BasicLayerManagerType { BLM_WIDGET, BLM_OFFSCREEN, BLM_INACTIVE };
+  /**
+   * Construct a BasicLayerManager which will have no default
+   * target context. SetDefaultTarget or BeginTransactionWithTarget
+   * must be called for any rendering to happen. PaintedLayers will not
+   * be retained.
+   */
+  explicit BasicLayerManager(BasicLayerManagerType aType);
+  /**
+   * Construct a BasicLayerManager which will have no default
+   * target context. SetDefaultTarget or BeginTransactionWithTarget
+   * must be called for any rendering to happen. PaintedLayers will be
+   * retained; that is, we will try to retain the visible contents of
+   * PaintedLayers as cairo surfaces. We create PaintedLayer buffers by
+   * creating similar surfaces to the default target context, or to
+   * aWidget's GetThebesSurface if there is no default target context, or
+   * to the passed-in context if there is no widget and no default
+   * target context.
+   *
+   * This does not keep a strong reference to the widget, so the caller
+   * must ensure that the widget outlives the layer manager or call
+   * ClearWidget before the widget dies.
+   */
+  explicit BasicLayerManager(nsIWidget* aWidget);
+
+ protected:
+  virtual ~BasicLayerManager();
+
+ public:
+  BasicLayerManager* AsBasicLayerManager() override { return this; }
+
+  /**
+   * Set the default target context that will be used when BeginTransaction
+   * is called. This can only be called outside a transaction.
+   *
+   * aDoubleBuffering can request double-buffering for drawing to the
+   * default target. When BUFFERED, the layer manager avoids blitting
+   * temporary results to aContext and then overpainting them with final
+   * results, by using a temporary buffer when necessary. In BUFFERED
+   * mode we always completely overwrite the contents of aContext's
+   * destination surface (within the clip region) using OP_SOURCE.
+   */
+  void SetDefaultTarget(gfxContext* aContext);
+  virtual void SetDefaultTargetConfiguration(BufferMode aDoubleBuffering,
+                                             ScreenRotation aRotation);
+  gfxContext* GetDefaultTarget() { return mDefaultTarget; }
+
+  nsIWidget* GetRetainerWidget() { return mWidget; }
+  void ClearRetainerWidget() { mWidget = nullptr; }
+
+  virtual bool IsWidgetLayerManager() override { return mWidget != nullptr; }
+  virtual bool IsInactiveLayerManager() override {
+    return mType == BLM_INACTIVE;
+  }
+
+  virtual bool BeginTransaction(const nsCString& aURL = nsCString()) override;
+  virtual bool BeginTransactionWithTarget(
+      gfxContext* aTarget, const nsCString& aURL = nsCString()) override;
+  virtual bool EndEmptyTransaction(
+      EndTransactionFlags aFlags = END_DEFAULT) override;
+  virtual void EndTransaction(
+      DrawPaintedLayerCallback aCallback, void* aCallbackData,
+      EndTransactionFlags aFlags = END_DEFAULT) override;
+  void AbortTransaction();
+
+  virtual void SetRoot(Layer* aLayer) override;
+
+  virtual already_AddRefed<PaintedLayer> CreatePaintedLayer() override;
+  virtual already_AddRefed<ContainerLayer> CreateContainerLayer() override;
+  virtual already_AddRefed<ImageLayer> CreateImageLayer() override;
+  virtual already_AddRefed<CanvasLayer> CreateCanvasLayer() override;
+  virtual already_AddRefed<ColorLayer> CreateColorLayer() override;
+  virtual already_AddRefed<ReadbackLayer> CreateReadbackLayer() override;
+  virtual ImageFactory* GetImageFactory();
+
+  virtual LayersBackend GetBackendType() override {
+    return LayersBackend::LAYERS_BASIC;
+  }
+  virtual void GetBackendName(nsAString& name) override {
+    name.AssignLiteral("Basic");
+  }
+
+  bool InConstruction() { return mPhase == PHASE_CONSTRUCTION; }
+#ifdef DEBUG
+  bool InDrawing() { return mPhase == PHASE_DRAWING; }
+  bool InForward() { return mPhase == PHASE_FORWARD; }
+#endif
+  bool InTransaction() { return mPhase != PHASE_NONE; }
+
+  gfxContext* GetTarget() { return mTarget; }
+  void SetTarget(gfxContext* aTarget) {
+    mUsingDefaultTarget = false;
+    mTarget = aTarget;
+  }
+  bool IsRetained() { return mWidget != nullptr; }
+
+  virtual const char* Name() const override { return "Basic"; }
+
+  // Clear the cached contents of this layer tree.
+  virtual void ClearCachedResources(Layer* aSubtree = nullptr) override;
+
+  void SetTransactionIncomplete() { mTransactionIncomplete = true; }
+  bool IsTransactionIncomplete() { return mTransactionIncomplete; }
+
+  struct PushedGroup {
+    PushedGroup()
+        : mFinalTarget(nullptr),
+          mNeedsClipToVisibleRegion(false),
+          mOperator(gfx::CompositionOp::OP_COUNT),
+          mOpacity(0.0f) {}
+    gfxContext* mFinalTarget;
+    RefPtr<gfxContext> mGroupTarget;
+    nsIntRegion mVisibleRegion;
+    bool mNeedsClipToVisibleRegion;
+    gfx::IntPoint mGroupOffset;
+    gfx::CompositionOp mOperator;
+    gfx::Float mOpacity;
+    RefPtr<gfx::SourceSurface> mMaskSurface;
+    gfx::Matrix mMaskTransform;
+  };
+
+  // Construct a PushedGroup for a specific layer.
+  // Return false if it has some errors in PushGroupForLayer(). Then, the
+  // "aGroupResult" is unavailable for future using.
+  bool PushGroupForLayer(gfxContext* aContext, Layer* aLayerContext,
+                         const nsIntRegion& aRegion, PushedGroup& aGroupResult);
+
+  void PopGroupForLayer(PushedGroup& aGroup);
+
+  virtual bool IsCompositingCheap() override { return false; }
+  virtual int32_t GetMaxTextureSize() const override { return INT32_MAX; }
+  bool CompositorMightResample() { return mCompositorMightResample; }
+
+  TimeStamp GetCompositionTime() const { return mCompositionTime; }
+
+ protected:
+  enum TransactionPhase {
+    PHASE_NONE,
+    PHASE_CONSTRUCTION,
+    PHASE_DRAWING,
+    PHASE_FORWARD
+  };
+  TransactionPhase mPhase;
+
+  // This is the main body of the PaintLayer routine which will if it has
+  // children, recurse into PaintLayer() otherwise it will paint using the
+  // underlying Paint() method of the Layer. It will not do both.
+  void PaintSelfOrChildren(PaintLayerContext& aPaintContext,
+                           gfxContext* aGroupTarget);
+
+  // Paint the group onto the underlying target. This is used by PaintLayer to
+  // flush the group to the underlying target.
+  void FlushGroup(PaintLayerContext& aPaintContext,
+                  bool aNeedsClipToVisibleRegion);
+
+  // Paints aLayer to mTarget.
+  void PaintLayer(gfxContext* aTarget, Layer* aLayer,
+                  DrawPaintedLayerCallback aCallback, void* aCallbackData);
+
+  // Clear the contents of a layer
+  void ClearLayer(Layer* aLayer);
+
+  bool EndTransactionInternal(DrawPaintedLayerCallback aCallback,
+                              void* aCallbackData,
+                              EndTransactionFlags aFlags = END_DEFAULT);
+
+  void FlashWidgetUpdateArea(gfxContext* aContext);
+
+  void SetCompositionTime(TimeStamp aTimeStamp) {
+    mCompositionTime = aTimeStamp;
+  }
+
+  // Widget whose surface should be used as the basis for PaintedLayer
+  // buffers.
+  nsIWidget* mWidget;
+  // The default context for BeginTransaction.
+  RefPtr<gfxContext> mDefaultTarget;
+  // The context to draw into.
+  RefPtr<gfxContext> mTarget;
+  // Image factory we use.
+  RefPtr<ImageFactory> mFactory;
+
+  BufferMode mDoubleBuffering;
+  BasicLayerManagerType mType;
+  bool mUsingDefaultTarget;
+  bool mTransactionIncomplete;
+  bool mCompositorMightResample;
+
+  TimeStamp mCompositionTime;
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif /* GFX_BASICLAYERS_H */