fix memory leak in TextBlobCacheTest

tests/TextBlobCacheTest.cpp

Index: tests/TextBlobCacheTest.cpp
diff --git a/tests/TextBlobCacheTest.cpp b/tests/TextBlobCacheTest.cpp
index 1c6596258b5b4bd34f1aec39a295ec14169592a3..e2fa554c9c09757c83823c1cbf0d89e2ca599989 100644
--- a/tests/TextBlobCacheTest.cpp
+++ b/tests/TextBlobCacheTest.cpp
@@ -25,7 +25,8 @@
 #include "GrContextFactory.h"
 
 struct TextBlobWrapper {
-    explicit TextBlobWrapper(const SkTextBlob* blob) : fBlob(SkRef(blob)) {}
+    // This class assumes it 'owns' the textblob it wraps, and thus does not need to take a ref
+    explicit TextBlobWrapper(const SkTextBlob* blob) : fBlob(blob) {}
     TextBlobWrapper(const TextBlobWrapper& blob) : fBlob(SkRef(blob.fBlob.get())) {}
 
     SkAutoTUnref<const SkTextBlob> fBlob;