diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/include/effects/SkLayerDrawLooper.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/include/effects/SkLayerDrawLooper.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,180 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkLayerDrawLooper_DEFINED
+#define SkLayerDrawLooper_DEFINED
+
+#include "SkDrawLooper.h"
+#include "SkPaint.h"
+#include "SkPoint.h"
+#include "SkXfermode.h"
+
+class SK_API SkLayerDrawLooper : public SkDrawLooper {
+public:
+    SK_DECLARE_INST_COUNT(SkLayerDrawLooper)
+
+            SkLayerDrawLooper();
+    virtual ~SkLayerDrawLooper();
+
+    /**
+     *  Bits specifies which aspects of the layer's paint should replace the
+     *  corresponding aspects on the draw's paint.
+     *  kEntirePaint_Bits means use the layer's paint completely.
+     *  0 means ignore the layer's paint... except for fColorMode, which is
+     *  always applied.
+     */
+    enum Bits {
+        kStyle_Bit      = 1 << 0,   //!< use this layer's Style/stroke settings
+        kTextSkewX_Bit  = 1 << 1,   //!< use this layer's textskewx
+        kPathEffect_Bit = 1 << 2,   //!< use this layer's patheffect
+        kMaskFilter_Bit = 1 << 3,   //!< use this layer's maskfilter
+        kShader_Bit     = 1 << 4,   //!< use this layer's shader
+        kColorFilter_Bit = 1 << 5,  //!< use this layer's colorfilter
+        kXfermode_Bit   = 1 << 6,   //!< use this layer's xfermode
+
+        /**
+         *  Use the layer's paint entirely, with these exceptions:
+         *  - We never override the draw's paint's text_encoding, since that is
+         *    used to interpret the text/len parameters in draw[Pos]Text.
+         *  - Color is always computed using the LayerInfo's fColorMode.
+         */
+        kEntirePaint_Bits = -1
+
+    };
+    typedef int32_t BitFlags;
+
+    /**
+     *  Info for how to apply the layer's paint and offset.
+     *
+     *  fColorMode controls how we compute the final color for the layer:
+     *      The layer's paint's color is treated as the SRC
+     *      The draw's paint's color is treated as the DST
+     *      final-color = Mode(layers-color, draws-color);
+     *  Any SkXfermode::Mode will work. Two common choices are:
+     *      kSrc_Mode: to use the layer's color, ignoring the draw's
+     *      kDst_Mode: to just keep the draw's color, ignoring the layer's
+     */
+    struct SK_API LayerInfo {
+        BitFlags            fPaintBits;
+        SkXfermode::Mode    fColorMode;
+        SkVector            fOffset;
+        bool                fPostTranslate; //!< applies to fOffset
+
+        /**
+         *  Initial the LayerInfo. Defaults to settings that will draw the
+         *  layer with no changes: e.g.
+         *      fPaintBits == 0
+         *      fColorMode == kDst_Mode
+         *      fOffset == (0, 0)
+         */
+        LayerInfo();
+    };
+
+    /**
+     *  Call for each layer you want to add (from top to bottom).
+     *  This returns a paint you can modify, but that ptr is only valid until
+     *  the next call made to addLayer().
+     */
+    SkPaint* addLayer(const LayerInfo&);
+
+    /**
+     *  This layer will draw with the original paint, at the specified offset
+     */
+    void addLayer(SkScalar dx, SkScalar dy);
+
+    /**
+     *  This layer will with the original paint and no offset.
+     */
+    void addLayer() { this->addLayer(0, 0); }
+
+    /// Similar to addLayer, but adds a layer to the top.
+    SkPaint* addLayerOnTop(const LayerInfo&);
+
+    virtual SkDrawLooper::Context* createContext(SkCanvas*, void* storage) const SK_OVERRIDE;
+
+    virtual size_t contextSize() const SK_OVERRIDE { return sizeof(LayerDrawLooperContext); }
+
+    SK_TO_STRING_OVERRIDE()
+
+    /// Implements Flattenable.
+    virtual Factory getFactory() const SK_OVERRIDE { return CreateProc; }
+    static SkFlattenable* CreateProc(SkReadBuffer& buffer);
+
+protected:
+    virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
+
+private:
+    struct Rec {
+        Rec*    fNext;
+        SkPaint fPaint;
+        LayerInfo fInfo;
+    };
+    Rec*    fRecs;
+    Rec*    fTopRec;
+    int     fCount;
+
+    // state-machine during the init/next cycle
+    class LayerDrawLooperContext : public SkDrawLooper::Context {
+    public:
+        explicit LayerDrawLooperContext(const SkLayerDrawLooper* looper);
+
+    protected:
+        virtual bool next(SkCanvas*, SkPaint* paint) SK_OVERRIDE;
+
+    private:
+        Rec* fCurrRec;
+
+        static void ApplyInfo(SkPaint* dst, const SkPaint& src, const LayerInfo&);
+    };
+
+    class MyRegistrar : public SkFlattenable::Registrar {
+    public:
+        MyRegistrar();
+    };
+
+    typedef SkDrawLooper INHERITED;
+
+public:
+    class SK_API Builder {
+    public:
+        Builder();
+        ~Builder();
+
+        /**
+         *  Call for each layer you want to add (from top to bottom).
+         *  This returns a paint you can modify, but that ptr is only valid until
+         *  the next call made to addLayer().
+         */
+        SkPaint* addLayer(const LayerInfo&);
+
+        /**
+         *  This layer will draw with the original paint, at the specified offset
+         */
+        void addLayer(SkScalar dx, SkScalar dy);
+
+        /**
+         *  This layer will with the original paint and no offset.
+         */
+        void addLayer() { this->addLayer(0, 0); }
+
+        /// Similar to addLayer, but adds a layer to the top.
+        SkPaint* addLayerOnTop(const LayerInfo&);
+
+        /**
+          * Pass list of layers on to newly built looper and return it. This will
+          * also reset the builder, so it can be used to build another looper.
+          */
+        SkLayerDrawLooper* detachLooper();
+
+    private:
+        Rec* fRecs;
+        Rec* fTopRec;
+        int  fCount;
+    };
+};
+
+#endif