Adding more validation

src/effects/SkOffsetImageFilter.cpp

 /*
  * Copyright 2012 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.
  */
 
 #include "SkOffsetImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 61 matching lines @@
 void SkOffsetImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writePoint(fOffset);
 }
 
 SkOffsetImageFilter::SkOffsetImageFilter(SkScalar dx, SkScalar dy, SkImageFilter* input,
                                          const CropRect* cropRect) : INHERITED(input, cropRect) {
     fOffset.set(dx, dy);
 }
 
-SkOffsetImageFilter::SkOffsetImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
+SkOffsetImageFilter::SkOffsetImageFilter(SkFlattenableReadBuffer& buffer)
+  : INHERITED(1, buffer) {
     buffer.readPoint(&fOffset);
     buffer.validate(SkScalarIsFinite(fOffset.fX) &&
                     SkScalarIsFinite(fOffset.fY));
 }