More IFX_ interface cleanup.

core/fxcrt/include/fx_stream.h

Index: core/fxcrt/include/fx_stream.h
diff --git a/core/fxcrt/include/fx_stream.h b/core/fxcrt/include/fx_stream.h
index ba72994f363785a01b0a67d5c8514d139b5ec00c..a91b59f2856c0ccf80fee579b2c2a5e5fb658443 100644
--- a/core/fxcrt/include/fx_stream.h
+++ b/core/fxcrt/include/fx_stream.h
@@ -79,7 +79,7 @@ class IFX_StreamRead {
   virtual size_t ReadBlock(void* buffer, size_t size) = 0;
 };
 
-class IFX_FileRead : IFX_StreamRead {
+class IFX_FileRead : public IFX_StreamRead {
  public:
   // IFX_StreamRead:
   void Release() override = 0;