force readbuffer clients to use specialized readFoo for flattenables

src/core/SkImageFilter.cpp

Index: src/core/SkImageFilter.cpp
diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 3b7de25c93ed1ca5b51b1154493789745878510e..c8c0c4dbf8257000d8eaa9bb07cf788a6730849d 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -68,7 +68,7 @@ SkImageFilter::SkImageFilter(SkFlattenableReadBuffer& buffer)
     : fInputCount(buffer.readInt()), fInputs(new SkImageFilter*[fInputCount]) {
     for (int i = 0; i < fInputCount; i++) {
         if (buffer.readBool()) {
-            fInputs[i] = static_cast<SkImageFilter*>(buffer.readFlattenable());
+            fInputs[i] = buffer.readImageFilter();
         } else {
             fInputs[i] = NULL;
         }