Add whitelist parameter to refEncodedData

src/core/SkImageCacherator.h

Index: src/core/SkImageCacherator.h
diff --git a/src/core/SkImageCacherator.h b/src/core/SkImageCacherator.h
index 7e146182c7ac3a763e7d431a262f5cd06677ca01..003088478b973169cdf1cb744753a1dc12135ff0 100644
--- a/src/core/SkImageCacherator.h
+++ b/src/core/SkImageCacherator.h
@@ -8,6 +8,7 @@
 #ifndef SkImageCacherator_DEFINED
 #define SkImageCacherator_DEFINED
 
+#include "SkImage.h"
 #include "SkImageGenerator.h"
 #include "SkMutex.h"
 #include "SkTemplates.h"
@@ -101,4 +102,14 @@ private:
     friend class GrImageTextureMaker;
 };
 
+// Exposed so it can be tested, not meant for external usage per-se
+//
+class SkGpuFormatWhitelist : public SkImageGenerator::RefEncodedWhitelist {
+    GrContext* fCtx;
+public:
+    SkGpuFormatWhitelist(GrContext* ctx) : fCtx(ctx) {}
+
+    bool includes(SkEncodedFormat format) override;
+};
+
 #endif