Adding more validation

include/core/SkImageFilter.h

Index: include/core/SkImageFilter.h
diff --git a/include/core/SkImageFilter.h b/include/core/SkImageFilter.h
index 56ebc2b77b67caa55dea89c12b64245282946cee..13ffa2b03fab890ae546d120ad86959b5cac336e 100644
--- a/include/core/SkImageFilter.h
+++ b/include/core/SkImageFilter.h
@@ -146,6 +146,14 @@ public:
     SK_DEFINE_FLATTENABLE_TYPE(SkImageFilter)
 
 protected:
+    // Filters either 1, 2 or N number of inputs
+    // No filter should reasonably have more than 65535 inputs
+    enum MaxInputCount {
+        kOneInput = 1,
+        kTwoInputs = 2,
+        kManyInputs = 65535,
+    };
+
     SkImageFilter(int inputCount, SkImageFilter** inputs, const CropRect* cropRect = NULL);
 
     // Convenience constructor for 1-input filters.
@@ -156,7 +164,7 @@ protected:
 
     virtual ~SkImageFilter();
 
-    explicit SkImageFilter(SkFlattenableReadBuffer& rb);
+    explicit SkImageFilter(SkFlattenableReadBuffer& rb, int maxInputCount);
 
     virtual void flatten(SkFlattenableWriteBuffer& wb) const SK_OVERRIDE;