Only run test_wrapped_resources() when GL is active

tests/ResourceCacheTest.cpp

Index: tests/ResourceCacheTest.cpp
diff --git a/tests/ResourceCacheTest.cpp b/tests/ResourceCacheTest.cpp
index 0b7cb10fa33b9ffa575b764e95077bb926bbb0dd..7e7824a5400aec6770c2205266f0d84b86baedbf 100644
--- a/tests/ResourceCacheTest.cpp
+++ b/tests/ResourceCacheTest.cpp
@@ -176,7 +176,8 @@ static void test_stencil_buffers(skiatest::Reporter* reporter, GrContext* contex
 
 static void test_wrapped_resources(skiatest::Reporter* reporter, GrContext* context) {
     const GrGpu* gpu = context->getGpu();
-    if (!gpu) {
+    // this test is only valid for GL
+    if (!gpu || !gpu->glContextForTesting()) {
         return;
     }