Initial error handling code

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 "SkMatrix.h"
@@ skipping 32 matching lines @@
     buffer.writePoint(fOffset);
 }
 
 SkOffsetImageFilter::SkOffsetImageFilter(SkScalar dx, SkScalar dy,
                                          SkImageFilter* input) : INHERITED(input) {
     fOffset.set(dx, dy);
 }
 
 SkOffsetImageFilter::SkOffsetImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
     buffer.readPoint(&fOffset);
+    buffer.validate(SkScalarIsFinite(fOffset.fX) &&
+                    SkScalarIsFinite(fOffset.fY));
 }