Fix ImageFilter fuzzer issue

src/core/SkPicturePlayback.h

Index: src/core/SkPicturePlayback.h
diff --git a/src/core/SkPicturePlayback.h b/src/core/SkPicturePlayback.h
index ca6ad1ade47f6aac9a39ea3d44fbd9cbdec51bf1..7cedaeb499f3cf801c30d1759f3b9b18c01c5556 100644
--- a/src/core/SkPicturePlayback.h
+++ b/src/core/SkPicturePlayback.h
@@ -38,13 +38,13 @@ protected:
     // The offset of the current operation when within the draw method
     size_t fCurOffset;
 
-    void handleOp(SkReader32* reader,
+    void handleOp(SkReadBuffer* reader,
                   DrawType op,
                   uint32_t size,
                   SkCanvas* canvas,
                   const SkMatrix& initialMatrix);
 
-    static DrawType ReadOpAndSize(SkReader32* reader, uint32_t* size);
+    static DrawType ReadOpAndSize(SkReadBuffer* reader, uint32_t* size);
 
     class AutoResetOpID {
     public: