Add outline of new GrContext hierarchy

This begins the process of splitting GrContext into:

GrContext_Base, GrImageContext, GrRecordingContext and GrDirectContext.

Change-Id: I3c43045f2a5549b049e95791d65f74d4e16de36f
Reviewed-on: https://skia-review.googlesource.com/c/186878
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/tests/DeferredDisplayListTest.cpp b/tests/DeferredDisplayListTest.cpp
index e20bc82..dfaa33a 100644
--- a/tests/DeferredDisplayListTest.cpp
+++ b/tests/DeferredDisplayListTest.cpp
@@ -53,7 +53,7 @@
                                              GrPixelConfig config) {
     const GrCaps* caps = context->contextPriv().caps();
 
-    switch (context->contextPriv().getBackend()) {
+    switch (context->backend()) {
     case GrBackendApi::kOpenGL: {
         const GrGLCaps* glCaps = static_cast<const GrGLCaps*>(caps);
         GrGLStandard standard = glCaps->standard();