[WIP] Add Context to SkDrawLooper.

include/effects/SkLayerDrawLooper.h

 /*
  * 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
 
@@ skipping 76 matching lines @@
     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&);
 
-    // overrides from SkDrawLooper
-    virtual void init(SkCanvas*);
-    virtual bool next(SkCanvas*, SkPaint* paint);
+    virtual SkDrawLooper::Context* createContext(SkCanvas*, void* storage) const SK_OVERRIDE;
+
+    virtual size_t contextSize() const SK_OVERRIDE { return sizeof(LayerDrawLooperContext); }
 
     SK_DEVELOPER_TO_STRING()
 
     /// 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
-    Rec* fCurrRec;
+    class LayerDrawLooperContext : public SkDrawLooper::Context {
+    public:
+        explicit LayerDrawLooperContext(const SkLayerDrawLooper* looper);
 
-    static void ApplyInfo(SkPaint* dst, const SkPaint& src, const LayerInfo&);
+    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 {
@@ skipping 28 matching lines @@
         SkLayerDrawLooper* detachLooper();
 
     private:
         Rec* fRecs;
         Rec* fTopRec;
         int  fCount;
     };
 };
 
 #endif