Remove many uses of kSkia8888 and kSkiaGamma8888

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3405

Change-Id: Ie920f4bcbb3dd28114a66f2363643bb10009b840
Reviewed-on: https://skia-review.googlesource.com/3405
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/tests/DFPathRendererTest.cpp b/tests/DFPathRendererTest.cpp
index d36c1684..30ca17d 100644
--- a/tests/DFPathRendererTest.cpp
+++ b/tests/DFPathRendererTest.cpp
@@ -65,7 +65,7 @@
     }
     sk_sp<GrDrawContext> dc(ctxInfo.grContext()->makeDrawContext(SkBackingFit::kApprox,
                                                                  800, 800,
-                                                                 kSkia8888_GrPixelConfig,
+                                                                 kRGBA_8888_GrPixelConfig,
                                                                  nullptr,
                                                                  0,
                                                                  kTopLeft_GrSurfaceOrigin));