Make SkBlend_optsTests fail rather than crash when resources are missing

tests/SkBlend_optsTest.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <string>
 #include <tuple>
 #include <vector>
@@ skipping 44 matching lines @@
     Spec spec,
     std::string resourceName,
     skiatest::Reporter* reporter)
 {
     Blender blender;
     std::string name;
     std::tie(blender, name) = spec;
 
     std::string fileName = resourceName + ".png";
     sk_sp<SkImage> image = GetResourceAsImage(fileName.c_str());
-    SkASSERT(image != nullptr);
     if (image == nullptr) {
-        SkFAIL("image is NULL");
+        ERRORF(reporter, "image is NULL");
+        return;
     }
     SkBitmap bm;
     if (!as_IB(image)->getROPixels(&bm)) {
-        SkFAIL("Could not read resource");
+        ERRORF(reporter, "Could not read resource");
+        return;
     }
 
     SkPixmap pixmap;
     bm.peekPixels(&pixmap);
     SkASSERTF(pixmap.colorType() == kN32_SkColorType, "colorType: %d", pixmap.colorType());
     SkASSERT(pixmap.alphaType() != kUnpremul_SkAlphaType);
     const uint32_t* src = pixmap.addr32();
     const int width = pixmap.rowBytesAsPixels();
     SkASSERT(width > 0);
     SkASSERT(width < 4000);
@@ skipping 43 matching lines @@
 DEF_TEST(SkBlend_optsSqrtCheck, reporter) {
     for (int c = 0; c < 256; c++) {
         Sk4f i{(float)c};
         Sk4f ii = i * i;
         Sk4f s = ii.sqrt() + 0.5f;
         Sk4f sf = s.floor();
         REPORTER_ASSERT_MESSAGE(
             reporter, i[0] == sf[0], SkStringPrintf("i: %f, s: %f", i[0], sf[0]));
     }
 }