[WIP] Add Context to SkDrawLooper.

include/effects/SkBlurDrawLooper.h

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkBlurDrawLooper_DEFINED
 #define SkBlurDrawLooper_DEFINED
@@ skipping 25 matching lines @@
     };
 
     SkBlurDrawLooper(SkColor color, SkScalar sigma, SkScalar dx, SkScalar dy,
                      uint32_t flags = kNone_BlurFlag);
 
 //    SK_ATTR_DEPRECATED("use sigma version")
     SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy, SkColor color,
                      uint32_t flags = kNone_BlurFlag);
     virtual ~SkBlurDrawLooper();
 
-    // overrides from SkDrawLooper
-    virtual void init(SkCanvas*);
-    virtual bool next(SkCanvas*, SkPaint* paint);
+    virtual SkDrawLooper::DrawContext* init(
+            SkCanvas*, void* storage, size_t storageSize) const SK_OVERRIDE;
 
     SK_DEVELOPER_TO_STRING()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBlurDrawLooper)
 
 protected:
     SkBlurDrawLooper(SkReadBuffer&);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
 private:
     SkMaskFilter*   fBlur;
     SkColorFilter*  fColorFilter;
     SkScalar        fDx, fDy;
     SkColor         fBlurColor;
     uint32_t        fBlurFlags;
 
     enum State {
         kBeforeEdge,
         kAfterEdge,
         kDone
     };
-    State   fState;
+
+    class BlurDrawLooperContext : public SkDrawLooper::DrawContext {
+    public:
+        explicit BlurDrawLooperContext(const SkBlurDrawLooper* looper);
+
+        virtual bool next(SkCanvas* canvas, SkPaint* paint) SK_OVERRIDE;
+
+    private:
+        const SkBlurDrawLooper* fLooper;
+        State fState;
+    };
 
     void init(SkScalar sigma, SkScalar dx, SkScalar dy, SkColor color, uint32_t flags);
 
     typedef SkDrawLooper INHERITED;
 };
 
 #endif