fix memory leak in TextBlobCacheTest

tests/TextBlobCacheTest.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "sk_tool_utils.h"
 #include "SkCanvas.h"
 #include "SkPaint.h"
 #include "SkPoint.h"
 #include "SkTextBlob.h"
 #include "SkFontMgr.h"
 #include "SkGraphics.h"
 #include "SkSurface.h"
 #include "SkTypeface.h"
 
 #ifdef SK_BUILD_FOR_WIN
     #include "SkTypeface_win.h"
 #endif
 
 #include "Test.h"
 
 #if SK_SUPPORT_GPU
 #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;
 };
 
 static void draw(SkCanvas* canvas, int redraw, const SkTArray<TextBlobWrapper>& blobs) {
     int yOffset = 0;
     for (int r = 0; r < redraw; r++) {
         for (int i = 0; i < blobs.count(); i++) {
             const SkTextBlob* blob = blobs[i].fBlob.get();
@@ skipping 77 matching lines @@
 
     // test draw after free
     ctx->freeGpuResources();
     draw(canvas, 1, blobs);
 
     // test draw after abandon
     ctx->abandonContext();
     draw(canvas, 1, blobs);
 }
 #endif