Initial error handling code

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 11 matching lines @@
   , fShader(s)
   , fRect(rect) {
     SkASSERT(s);
     s->ref();
 }
 
 SkRectShaderImageFilter::SkRectShaderImageFilter(SkFlattenableReadBuffer& buffer)
   : INHERITED(buffer) {
     fShader = buffer.readFlattenableT<SkShader>();
     buffer.readRect(&fRect);
+    buffer.validateData(fRect.isValid());
 }
 
 void SkRectShaderImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.writeFlattenable(fShader);
     buffer.writeRect(fRect);
 }
 
 SkRectShaderImageFilter::~SkRectShaderImageFilter() {
@@ skipping 16 matching lines @@
 
     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(SkScalarCeilToInt(rect.width()),
                                                           SkScalarCeilToInt(rect.height())));
     SkCanvas canvas(device.get());
     SkPaint paint;
     paint.setShader(fShader);
     canvas.drawRect(rect, paint);
     *result = device.get()->accessBitmap(false);
     return true;
 }