Fixed issue found by clusterfuzz

include/core/SkReader32.h

Index: include/core/SkReader32.h
diff --git a/include/core/SkReader32.h b/include/core/SkReader32.h
index 7e8038d0ae3a7913cf3c5ee036b866b7720e0963..51e28ef146c062b29b2c9b5af5d98225a0911ac3 100644
--- a/include/core/SkReader32.h
+++ b/include/core/SkReader32.h
@@ -40,7 +40,7 @@ public:
     const void* peek() const { return fCurr; }
 
     size_t available() const { return fStop - fCurr; }
-    bool isAvailable(size_t size) const { return fCurr + size <= fStop; }
+    bool isAvailable(size_t size) const { return size <= this->available(); }
 
     void rewind() { fCurr = fBase; }