One signature for creating unit tests that run on premade GrContexts

tests/WritePixelsTest.cpp

Index: tests/WritePixelsTest.cpp
diff --git a/tests/WritePixelsTest.cpp b/tests/WritePixelsTest.cpp
index 6dda6ff89ee70f7beec92c40ad5d3962e7417d1e..669d885c96fb35d86b8add7baf8df4627592f404 100644
--- a/tests/WritePixelsTest.cpp
+++ b/tests/WritePixelsTest.cpp
@@ -406,7 +406,7 @@ DEF_TEST(WritePixels, reporter) {
     }
 }
 #if SK_SUPPORT_GPU
-DEF_GPUTEST_FOR_RENDERING_CONTEXTS(WritePixels_Gpu, reporter, context) {
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(WritePixels_Gpu, reporter, ctxInfo) {
     for (auto& origin : { kTopLeft_GrSurfaceOrigin, kBottomLeft_GrSurfaceOrigin }) {
         GrSurfaceDesc desc;
         desc.fFlags = kRenderTarget_GrSurfaceFlag;
@@ -414,8 +414,8 @@ DEF_GPUTEST_FOR_RENDERING_CONTEXTS(WritePixels_Gpu, reporter, context) {
         desc.fHeight = DEV_H;
         desc.fConfig = kSkia8888_GrPixelConfig;
         desc.fOrigin = origin;
-        SkAutoTUnref<GrTexture> texture(context->textureProvider()->createTexture(desc,
-                                                                                  SkBudgeted::kNo));
+        SkAutoTUnref<GrTexture> texture(
+            ctxInfo.fGrContext->textureProvider()->createTexture(desc, SkBudgeted::kNo));
         auto surface(SkSurface::MakeRenderTargetDirect(texture->asRenderTarget()));
         test_write_pixels(reporter, surface.get());
     }