Make existing unit tests only run on GL contexts

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1869503002

Review URL: https://codereview.chromium.org/1869503002
diff --git a/tests/BitmapCopyTest.cpp b/tests/BitmapCopyTest.cpp
index fb38c7e..9ae9ab7 100644
--- a/tests/BitmapCopyTest.cpp
+++ b/tests/BitmapCopyTest.cpp
@@ -639,7 +639,7 @@
 #include "SkColorPriv.h"
 /** Tests calling copyTo on a texture backed bitmap. Tests that all BGRA_8888/RGBA_8888 combinations
     of src and dst work. This test should be removed when SkGrPixelRef is removed. */
-DEF_GPUTEST_FOR_RENDERING_CONTEXTS(BitmapCopy_Texture, reporter, ctxInfo) {
+DEF_GPUTEST_FOR_GL_RENDERING_CONTEXTS(BitmapCopy_Texture, reporter, ctxInfo) {
     static const SkPMColor kData[] = {
         0xFF112233, 0xAF224499,
         0xEF004466, 0x80773311