Initial error handling code

src/effects/SkTestImageFilters.cpp

 
 #include "SkTestImageFilters.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkFlattenableBuffers.h"
 
 // Simple helper canvas that "takes ownership" of the provided device, so that
 // when this canvas goes out of scope, so will its device. Could be replaced
 // with the following:
 //
@@ skipping 60 matching lines @@
 }
 
 void SkDownSampleImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.writeScalar(fScale);
 }
 
 SkDownSampleImageFilter::SkDownSampleImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
     fScale = buffer.readScalar();
+    buffer.validate(SkScalarIsFinite(fScale));
 }