Use RGBA rather than N32 for GPU tests

This is to support a Mock backend that passes non-rendering context unit tests and has minimal config support.

Change-Id: I57c3ad2d347659d14382a8a7cf53424633bd86c6
Reviewed-on: https://skia-review.googlesource.com/21534
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/tests/ImageFilterTest.cpp b/tests/ImageFilterTest.cpp
index 95a1333..f843586 100644
--- a/tests/ImageFilterTest.cpp
+++ b/tests/ImageFilterTest.cpp
@@ -1828,11 +1828,10 @@
 }
 
 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(XfermodeImageFilterCroppedInput_Gpu, reporter, ctxInfo) {
-
-    sk_sp<SkSurface> surf(SkSurface::MakeRenderTarget(ctxInfo.grContext(),
-                                                      SkBudgeted::kNo,
-                                                      SkImageInfo::MakeN32Premul(1, 1)));
-
+    sk_sp<SkSurface> surf(SkSurface::MakeRenderTarget(
+            ctxInfo.grContext(),
+            SkBudgeted::kNo,
+            SkImageInfo::Make(1, 1, kRGBA_8888_SkColorType, kPremul_SkAlphaType)));
 
     SkCanvas* canvas = surf->getCanvas();
 
@@ -1840,8 +1839,9 @@
 }
 
 DEF_GPUTEST_FOR_ALL_CONTEXTS(ImageFilterBlurLargeImage_Gpu, reporter, ctxInfo) {
-    auto surface(SkSurface::MakeRenderTarget(ctxInfo.grContext(), SkBudgeted::kYes,
-                                             SkImageInfo::MakeN32Premul(100, 100)));
+    auto surface(SkSurface::MakeRenderTarget(
+            ctxInfo.grContext(), SkBudgeted::kYes,
+            SkImageInfo::Make(100, 100, kRGBA_8888_SkColorType, kPremul_SkAlphaType)));
     test_large_blur_input(reporter, surface->getCanvas());
 }
 #endif