Switch AlphaThresholdFilter over to new onFilterImage interface

include/core/SkImageFilter.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 SkImageFilter_DEFINED
 #define SkImageFilter_DEFINED
 
 #include "../private/SkTArray.h"
 #include "../private/SkTemplates.h"
 #include "../private/SkMutex.h"
 #include "SkFilterQuality.h"
 #include "SkFlattenable.h"
 #include "SkMatrix.h"
 #include "SkRect.h"
 #include "SkSurfaceProps.h"
 
+class GrContext;
 class GrFragmentProcessor;
 class GrTexture;
 class SkBaseDevice;
 class SkBitmap;
 class SkColorFilter;
 struct SkIPoint;
 class SkSpecialImage;
 
 /**
  *  Base class for image filters. If one is installed in the paint, then
@@ skipping 159 matching lines @@
      *  textures.  For single-pass effects, use asFragmentProcessor().  src is the
      *  source image for processing, as a texture-backed bitmap.  result is
      *  the destination bitmap, which should contain a texture-backed pixelref
      *  on success.  offset is the amount to translate the resulting image
      *  relative to the src when it is drawn. The default implementation does
      *  single-pass processing using asFragmentProcessor().
      */
     virtual bool filterImageGPUDeprecated(Proxy*, const SkBitmap& src, const Context&,
                                           SkBitmap* result, SkIPoint* offset) const;
 
+#if SK_SUPPORT_GPU
+    static sk_sp<SkSpecialImage> DrawWithFP(GrContext* context, 
+                                            sk_sp<GrFragmentProcessor> fp,
+                                            const SkIRect& bounds,
+                                            SkImageFilter::Proxy* proxy);
+#endif
+
     /**
      *  Returns whether this image filter is a color filter and puts the color filter into the
      *  "filterPtr" parameter if it can. Does nothing otherwise.
      *  If this returns false, then the filterPtr is unchanged.
      *  If this returns true, then if filterPtr is not null, it must be set to a ref'd colorfitler
      *  (i.e. it may not be set to NULL).
      */
     bool isColorFilterNode(SkColorFilter** filterPtr) const {
         return this->onIsColorFilterNode(filterPtr);
     }
@@ skipping 202 matching lines @@
                                SkBitmap* result, SkIPoint* offset) const;
 
     /**
      *  Return true (and return a ref'd colorfilter) if this node in the DAG is just a
      *  colorfilter w/o CropRect constraints.
      */
     virtual bool onIsColorFilterNode(SkColorFilter** /*filterPtr*/) const {
         return false;
     }
 
-    /** Given a "srcBounds" rect, computes destination bounds for this
-     *  destination bounds for this filter. "dstBounds" are computed by
-     *  transforming the crop rect by the context's CTM, applying it to the
-     *  initial bounds, and intersecting the result with the context's clip
-     *  bounds.  "srcBounds" (if non-null) are computed by intersecting the
-     *  initial bounds with "dstBounds", to ensure that we never sample
-     *  outside of the crop rect (this restriction may be relaxed in the
+    /** Given a "srcBounds" rect, computes destination bounds for this filter.
+     *  "dstBounds" are computed by transforming the crop rect by the context's
+     *  CTM, applying it to the initial bounds, and intersecting the result with
+     *  the context's clip bounds.  "srcBounds" (if non-null) are computed by
+     *  intersecting the initial bounds with "dstBounds", to ensure that we never
+     *  sample outside of the crop rect (this restriction may be relaxed in the
      *  future).
      */
     bool applyCropRect(const Context&, const SkIRect& srcBounds, SkIRect* dstBounds) const;
 
     /** A variant of the above call which takes the original source bitmap and
      *  source offset. If the resulting crop rect is not entirely contained by
      *  the source bitmap's bounds, it creates a new bitmap in "result" and
      *  pads the edges with transparent black. In that case, the srcOffset is
      *  modified to be the same as the bounds, since no further adjustment is
      *  needed by the caller. This version should only be used by filters
@@ skipping 57 matching lines @@
  */
 #define SK_IMAGEFILTER_UNFLATTEN_COMMON(localVar, expectedCount)    \
     Common localVar;                                                \
     do {                                                            \
         if (!localVar.unflatten(buffer, expectedCount)) {           \
             return NULL;                                            \
         }                                                           \
     } while (0)
 
 #endif