add asAShadowBlur for android to drawlooper

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 43 matching lines @@
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBlurDrawLooper)
 
 protected:
     SkBlurDrawLooper(SkColor color, SkScalar sigma, SkScalar dx, SkScalar dy,
                      uint32_t flags);
 
     SkBlurDrawLooper(SkReadBuffer&);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
+    virtual bool asABlurShadow(BlurShadowRec*) const SK_OVERRIDE;
+
 private:
     SkMaskFilter*   fBlur;
     SkColorFilter*  fColorFilter;
-    SkScalar        fDx, fDy;
+    SkScalar        fDx, fDy, fSigma;
     SkColor         fBlurColor;
     uint32_t        fBlurFlags;
 
     enum State {
         kBeforeEdge,
         kAfterEdge,
         kDone
     };
 
     class BlurDrawLooperContext : public SkDrawLooper::Context {
     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