Adding more validation

src/effects/SkBitmapSource.cpp

Index: src/effects/SkBitmapSource.cpp
diff --git a/src/effects/SkBitmapSource.cpp b/src/effects/SkBitmapSource.cpp
index 854df9df226bf2dbbe1ba92043f59a420632719c..5b949f75bc5a91551b98d700883cd7fc4eaac6a2 100644
--- a/src/effects/SkBitmapSource.cpp
+++ b/src/effects/SkBitmapSource.cpp
@@ -13,7 +13,7 @@ SkBitmapSource::SkBitmapSource(const SkBitmap& bitmap)
 }
 
 SkBitmapSource::SkBitmapSource(SkFlattenableReadBuffer& buffer)
-  : INHERITED(buffer) {
+  : INHERITED(buffer, SkImageFilter::kOneInput) {

[Stephen White, 2013/11/22 21:00:17]

This should probably zero inputs. In fact, the regular constructor should
probably be calling SkImageFilter(0, 0), instead of SkImageFilter(0).

(On a tangential note, we could probably rid of the one-arg constructor on the
base class, and call SkImageFilter(0, &arg) from the derived class instead.
Slightly harder to get rid of the two-arg version, sadly.)

     fBitmap.unflatten(buffer);
 }