Simplify flattening to just write enough to call the factory

src/effects/SkRectShaderImageFilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRectShaderImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 17 matching lines @@
     return SkNEW_ARGS(SkRectShaderImageFilter, (s, cropRect));
 }
 
 SkRectShaderImageFilter::SkRectShaderImageFilter(SkShader* s, const CropRect* cropRect)
   : INHERITED(0, NULL, cropRect)
   , fShader(s) {
     SkASSERT(s);
     s->ref();
 }
 
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
 SkRectShaderImageFilter::SkRectShaderImageFilter(SkReadBuffer& buffer)
   : INHERITED(0, buffer) {
     fShader = buffer.readShader();
 }
+#endif
+
+SkFlattenable* SkRectShaderImageFilter::CreateProc(SkReadBuffer& buffer) {
+    SK_IMAGEFILTER_UNFLATTEN_COMMON(0);
+    return Create(buffer.readShader(), &common.cropRect());
+}
 
 void SkRectShaderImageFilter::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
-
     buffer.writeFlattenable(fShader);
 }
 
 SkRectShaderImageFilter::~SkRectShaderImageFilter() {
     SkSafeUnref(fShader);
 }
 
 bool SkRectShaderImageFilter::onFilterImage(Proxy* proxy,
                                             const SkBitmap& source,
                                             const Context& ctx,
@@ skipping 17 matching lines @@
     paint.setShader(SkShader::CreateLocalMatrixShader(fShader, matrix))->unref();
 
     SkRect rect = SkRect::MakeWH(SkIntToScalar(bounds.width()), SkIntToScalar(bounds.height()));
     canvas.drawRect(rect, paint);
 
     *result = device.get()->accessBitmap(false);
     offset->fX = bounds.fLeft;
     offset->fY = bounds.fTop;
     return true;
 }