Add rowBytes to createTestingOnlyBackendTexture

This is pulled out of:

https://skia-review.googlesource.com/c/skia/+/151983 (Test YUV images in DDL)

The YUV images seem to like to have row padding.

Change-Id: I517d2b63678beeafef88f86148fca15862176780
Reviewed-on: https://skia-review.googlesource.com/156367
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/tests/WritePixelsTest.cpp b/tests/WritePixelsTest.cpp
index 82690a3..007f16b 100644
--- a/tests/WritePixelsTest.cpp
+++ b/tests/WritePixelsTest.cpp
@@ -457,7 +457,7 @@
 
     for (auto& origin : { kTopLeft_GrSurfaceOrigin, kBottomLeft_GrSurfaceOrigin }) {
         GrBackendTexture backendTex = gpu->createTestingOnlyBackendTexture(
-                nullptr, DEV_W, DEV_H, kSkia8888_GrPixelConfig, true, GrMipMapped::kNo);
+                nullptr, DEV_W, DEV_H, GrColorType::kRGBA_8888, true, GrMipMapped::kNo);
         if (!backendTex.isValid()) {
             continue;
         }