Add Make[backend] calls for creating GrContexts

Docs-Preview: https://skia.org/?cl=26369
Bug: skia:
Change-Id: I460ee63e466f85b05918479f068a2e5ca2d70550
Reviewed-on: https://skia-review.googlesource.com/26369
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/tools/fiddle/mesa_context.cpp b/tools/fiddle/mesa_context.cpp
index 3b3726b..89902ec 100644
--- a/tools/fiddle/mesa_context.cpp
+++ b/tools/fiddle/mesa_context.cpp
@@ -27,7 +27,5 @@
     if (!mesa) {
         return nullptr;
     }
-    return sk_sp<GrContext>(GrContext::Create(
-                kOpenGL_GrBackend,
-                reinterpret_cast<intptr_t>(mesa.get())));
+    return GrContext::MakeGL(mesa.get());
 }